In my recent posts about the structural design of the Falcon and Fairlane and Mustang, Cougar, and Maverick, I mentioned that (until about 1971) all these cars used the top of the fuel tank as part of the trunk floor. This type of “drop-in” gas tank has been frequently criticized as a safety hazard. Here’s why Ford originally adopted it, and why this type of tank might increase fire danger in a rear impact.
Building a Lighter Falcon (and Comet, and Fairlane, and …)
To understand why Ford adopted this type of gas tank, we must step back to the development of the original Ford Falcon in the late 1950s. As I’ve said previously, the Falcon program had extremely aggressive weight controls, something that became a Ford Motor Company fixation in the ’60s, particularly for low-end models. For context, I think it’s helpful to look briefly at how that worked.
Ford’s strategy for weight control in this era involved breaking down each area of a vehicle’s design into a series of Uniform Parts Classification groups. Each part in each group would be laid out, classified, weighed, labeled, and photographed. The weight of each component and each subgroup would be then closely scrutinized by design engineers, stress analysts, and weight analysts, looking for opportunities to simplify and cut weight, down to things like reducing paint thickness and eliminating chrome garnish moldings. Ford disassembled and analyzed competitors’ cars in the same way; the early stages of the Falcon program included a detailed weight analysis of several existing compact and subcompact vehicles.
Ford then did a paper study to set target weights for all of the car’s components. These were added up to produce the target weight for the whole car, which for the Falcon was originally 2,244.3 lb.
As Ford engineers H.L. Browne and John D. Collins explained later, “The weights were a commitment, not an opinion.” Any deviation from the target had to be explained in writing. Engineers could only change a target if management decided to change the “package,” such as by changing the styling or exterior dimensions. (For instance, during development, the Falcon was widened several inches to provide six-passenger capacity.) If testing and development showed that certain parts needed to be heavier for durability or functional reasons, there was intense pressure to find other areas where a little weight could be saved, to make up the difference.
Ford considered two proposals for the Falcon fuel tank location: one with the tank mounted under the floor, held in place by straps, and one with a “drop-in” fuel tank that formed part of the trunk floor, bolted in place. In both proposals, the fuel filler was at the rear, extending through the back panel.
Here’s the body structures department weight analysis report for these proposals. The handwritten text is not very legible, but it shows a total weight of 74.55 lb for the under-trunk tank (Proposal A) and 60.11 lb for the bolt-in tank (Proposal B), a difference of 14.44 lb. This was not a small savings when Ford engineers were fighting and clawing to save even a pound or two.
Although the above analysis doesn’t show it, the drop-in tank also had an additional benefit of helping to stiffen the trunk floor. The Falcon didn’t have a rear crossmember between the two rear rails other than the back support panel. So, even though the fuel tank was bolted in place, not welded, the metal fuel tank added to the rigidity of the rear end, which may also have saved a few pounds elsewhere.
Given the priorities of the Falcon program, I don’t think the selection of this option was a very difficult one. It was partly a matter of cost, but it was also very much about weight, which directly affected the Falcon’s fuel economy and performance goals.
Although the package weight of the 1960 Falcon eventually increased due to design and styling changes, the 1960 Ford Falcon Tudor sedan arrived with a base curb weight of only 2,387 lb, 500 lb lighter than a 2026 Honda Civic LX, whose overall dimensions are very similar to the old Falcon. The Falcon was almost 370 lb lighter than a 1960 Valiant V-100 sedan, about 300 lb lighter than a 1960 Lark VI two-door sedan, and 148 lb lighter than a four-cylinder 1962 Chevy II 100 two-door sedan. That weight advantage was due in part to weight-saving features like the drop-in gas tank. Obviously, the gas tank wasn’t solely responsible for that, but it played a minor but significant part.
After the Falcon, Ford then carried over the drop-in fuel tank to the new Comet sedan, which was originally just a Falcon with a longer tail and a different roof.
Having demonstrated the weight-saving and structural benefits of the drop-in tank, Ford subsequently adopted it for other cars, including the Mustang and Cougar, the 1966–1970 Fairlane/Falcon/Comet/Torino, and finally the 1970 Maverick. The drop-in gas tank was probably a bit cheaper than an under-trunk tank, but just as importantly, it was lighter and it stiffened the trunk floor, which remained useful even in somewhat bigger and more expensive vehicles than the penny-pinching early Falcon.
Two important excepts were station wagons and the Ranchero, which used a different style of tank strapped under the cargo area, with the filler on the left side.
Curiously, from 1966 through early 1970, when the Falcon sedan and coupe became cut-down Fairlanes, their fuel filler was relocated to the left side of the trunk, like the station wagons and Ranchero, although the tank was still bolted into the trunk floor as in earlier sedans.
In the Fairlane/Torino and Montego/Cyclone intermediates, the fuel filler remained in back, as on the Mustang and Cougar.
The Mustang, Cougar, and Maverick abandoned the drop-in fuel tank after 1970 in favor of an under-trunk gas tank, as seen above. The intermediate Torino and Montego followed suit after 1971.
The Maverick’s Comet sibling, which arrived for 1971, never used the drop-in tank.
If you’re wondering, the Ford Pinto DID NOT use a drop-in gas tank. On the Pinto, the fuel tank was attached with straps under the trunk floor, behind the axle, with the fuel filler on the left side. The much-publicized Pinto fuel system hazards were NOT related to the kind of fuel tanks I’m discussing here.
Drop-In Tanks a Fire Hazard?
All this background is secondary to the big question, which is whether the drop-in design was intrinsically less safe and more susceptible to fire than other fuel tank installations. The safety complaints made about the Ford drop-in gas tank boil down to four separate issues — let’s look at each of them.
First, there’s the issue that the fuel filler in the most common applications of the drop-in tank is located at the rear, extending through the back support panel, where it’s quite vulnerable in any but the slowest rear impacts.
This is a very reasonable concern, although a great many American cars of the ’60s, even ones that put the tank under the trunk floor, also had a centrally located rear filler — the ’68 Nova pictured above was typical. If Ford had gone with Proposal A for the Falcon gas tank, putting it under the trunk, sedans would still have had a rear-mounted fuel filler, which Ford considered more convenient, since you could fill up from a pump on either side of the car.
A second issue is that because the filler of the Ford drop-in tank is not shrouded at all, it’s vulnerable to damage from objects in the trunk as well as from collisions. This is also a very reasonable concern, and one that I often fret about when I see the exposed filler pipes in the trunks of other low-end American cars of the ’60s and ’70s. Here again, though, a lot of non-Ford cars that didn’t use drop-in fuel tanks posed similar problems, as illustrated by the Plymouth Duster pictured above. Even with its removable trunk floor in place to conceal the spare, the Valiant/Duster fuel filler pipe remained exposed.
The fuel filler of the 1966–1970 Falcon sedan and the Falcon/Fairlane/Comet wagons, mounted on the left side, might have been a bit less vulnerable in rear impacts, but in the later sedan and coupe models, the fuel filler pipe was even more exposed within the trunk, which doesn’t seem like a great improvement.
A third point is the contention, often raised in lawsuits, that Ford should have provided some kind of protective bulkhead between the trunk and the rear seat to keep the fuel tank from being pushed forward into the passenger compartment in a rear impact. This one is really a stretch for me because very, very few passenger vehicles then or now have such a barrier — nearly all hatchbacks and many sedans and coupes have folding rear seats, sometimes with a folding or removable package shelf. Also, even if the rear seats are fixed, installing a barrier behind the rear seat seems unlikely to provide much protection against either splashed gasoline or a fire starting in the trunk.
The fourth and most troublesome question is whether being bolted into the trunk floor makes the drop-in tank itself more vulnerable to damage. There are two facets to this: One is the possibility that using the top of the tank as part of the trunk floor may increase the risk of the tank being punctured, and the other is the risk that in a rear collision, stresses on the tank could cause it to separate and/or rupture, splashing its contents forward into the passenger compartment.
The drop-in fuel tank, which is fairly rigid, is bolted into the trunk floor between the rear side rails. If a collision violently distorts the structure to which the tank is firmly bolted, something’s gotta give — either the tank mounting bolts (leading to tank separation), the top of the tank itself (leading to rupture), or both. This seems to me the principal area where these tanks might be MORE hazardous than other contemporary gas tank arrangements. Unfortunately, it’s also the most difficult area to independently evaluate, since that would involve structural analysis of how the unit-body structure of these cars behave in a rear collision, and would probably require actual crash testing.
Accidents and Lawsuits
Over the years, Ford has been sued many times by people who had been burned when their Mustang, Falcon, Comet, Fairlane, or Maverick caught fire during a rear-impact accident. Many of those suits have been settled out of court, but some have gone to trial (and sometimes multiple appeals). Plaintiffs have produced various expert witnesses to testify that the drop-in tank was a defective design, and inherently dangerous.
Courts and juries have sometimes agreed. In 1971, for example, a federal jury awarded $400,000 in damages to a New York man who sued Ford after his then-new 1967 Mustang burned and exploded in an accident on the Queensboro Bridge. Although Ford Motor Company was not a party to Buehler v. Whalen, an Illinois lawsuit involving the crash of a 1966 Ford Fairlane (which also used the drop-in fuel tank), the Supreme Court of Illinois eventually ruled (374 N.E.2d 460 (1978)), based on previous liability case precedents, that “cars equipped with a fuel system of the type used on the Fairlane represent a design defect because of the vulnerability to impact and the risk of fire spreading into the passenger compartment.”
An NHTSA investigation in the mid-’70s concluded that the Ford drop-in fuel tanks “present no fire hazard which does not also exist in … other fuel tank systems.” Even assuming that was true, it wasn’t exactly a confidence-inspiring conclusion, and well into the 1990s, some safety advocates continued vainly trying to force Ford to recall and retrofit every single surviving car originally fitted with these tanks.
In 1975, the federal General Services Administration (GSA) pointed out that Mustangs and Falcons were involved in five of the eight fuel system leakage accidents the GSA had recorded that involved gas tank separation, and proposed that the NHTSA investigate more thoroughly. NHTSA staff engineers responded that they didn’t think the accidents were relatable to the federal fuel tank integrity standard (FMVSS 301) — which at the time didn’t yet apply to rear impacts — and contended that the Falcon and Mustang shouldn’t be considered in the same breath because they were “structurally unrelated” (a very arguable point!).
Ford Motor Company apparently had internal evidence that the drop-in gas tank was susceptible to rupture in rear impacts. The late Harold C. MacDonald, chief of Ford Division product engineering in the ’60s, admitted as much in a deposition, and auto safety consultant Byron Bloch claimed that there were half a dozen internal Ford crash test results reporting fuel tank leakage or rupture in rear impacts. Former Ford engineer Peter Bertelson later told CBS News that by 1966, “all the engineering executives were aware of the problems of the drop-in tank.” Safety advocate and lobbyist Joan Claybrook, who headed the NHTSA during the Carter administration, claimed that during the early ’70s NHTSA investigation (completed before her appointment), Ford had deliberately withheld crash test results showing fuel tank rupture in medium-speed (21 to 31 mph) rear impacts. Ford denied that it had done anything wrong, or that it had withheld any relevant information from the NHTSA.
When interviewed by CBS in 1999, Lee Iacocca scoffed at the idea that his Mustang “had more problems or severity of problems than any other car in its class,” although he admitted that safety “wasn’t the priority” in its design.
A Hazard, But Maybe Not a Unique Hazard?
Evaluating automotive safety hazards or defects is challenging. The circumstances of each accident are unique, with lots of moving parts and contributing factors. There’s really no neutral point of view: Manufacturers are usually very reluctant to do any more than the bare minimum the law requires (and not even always that much), and are violently allergic to even tacit admissions of liability. Safety experts will happily testify under oath than any car that doesn’t submerge each occupant in impact-absorbing, fire-retardant foam surrounded by armor plate is obviously defective. Then, there’s the contingent of third-party apologists who will insist that even the most obvious hazard is just nanny-state propaganda and no big deal if you’re as smart and talented as THEY are (maybe because that helps them reassure themselves that they’re in no danger). Meanwhile, accident victims or their survivors, who may have suffered truly grievous losses, are eager for justice and recompense.
When it comes to the Ford drop-in gas tank, I think there are really two questions: 1) Did the drop-in tank design present a safety hazard, and 2), did it present more of a safety hazard than other gas tanks of the time? For what it’s worth, my take goes something like this:
- Was this gas tank design a safety hazard? Certainly — at the very least, both the rear-mounted filler and the exposed filler pipe were vulnerable in ways that were pretty manifestly hazardous, even though those hazards were by no means unique to this design, or to Ford products.
- Was this gas tank installation MORE hazardous than other gas tanks of the time? Maybe — as I said above, the possibility that the way the tank is bolted to the trunk floor might make it more vulnerable to being punctured or ruptured in a rear impact is hard to really quantify without crash testing, but I certainly wouldn’t discount it, especially if Ford had confidential crash test reports demonstrating the risk.
In 2004, the NHTSA revised the FMVSS 301 fuel system integrity standard (which you can see at 49 CFR 571.301), adding much stricter requirements for fuel leakage in rear and side impacts, beginning with the 2007 model year. Of course, that doesn’t help owners of older cars, whatever kind of fuel tanks they have.
Statistically, fires resulting from passenger car accidents are rare — a 1981 analysis cited estimates of about one fire per 1,000 accidents overall and about one fire per 500 police-reported accidents. However, when vehicular fires do occur in an accident, they can be truly horrific. For example, in 1985, Florida teenager Marlo Mahne was badly burned when the 1967 Mustang in which she was riding suffered a fuel tank rupture and caught fire after being rear-ended. She survived, but suffered third- and fourth-degree burns over 70 percent of her body and ended up blind in one eye.
There are aftermarket add-ons that are supposed to help protect the drop-in tank, including fuel tank cover plates and steel bulkheads, although how beneficial those may be in an accident is hard to say. (If I owned one of these cars, I’d be tempted to add some kind of cage around the filler pipe to protect it from objects sliding around in the trunk, but that wouldn’t do much good if the car was rear-ended.) There’s also the option of replacing the tank with a racing-style fuel cell with rubber fuel bladders surrounded by foam baffles, limiting the amount of fuel that leaks even if the tank ruptures — probably a more effective solution from a safety standpoint, but also a very expensive one. Whether it’s worth it isn’t something I can say.
Related Reading
CC Tech: Ford Falcon, Comet, and Fairlane – How These Unit-Body Fords Were Alike (And Different) (by me)
CC Tech: How the Mustang, Cougar, And Maverick Differed From The Original Ford Falcon Platform (by me)
It’s an interesting question. The issue I can see with the drop in design is that in a crash it would be well fixed in place and therefore would act to take up the energy, causing it to deform. The other designs – I could see the straps failing, especially if they were rusted. Is that the intended design – that the strapped ones would break off rather than deforming?
Across all of them I found the filler placement pretty concerning! The only car of that era I’ve owned was a Citroen DS – which has the fuel filler well isolated from the luggage compartment, and the tank located under the rear seat (so, further from a rear end collision, but potentially worse in a side impact)
Haha, I’ve been in the back of a DS; it would never have occurred to me I was sat atop the gas tank although in racing such things are done. Emerson Fittipaldi’s 1969 Bimotor 3200 (a twin-engined VW Beetle) had an aluminum tank holding 100 liters (26.4 gallons (US); 22 gallons (Imperial)) of an ethanol cocktail and it was shaped specifically for the car: it was the driver’s seat.
Statistically, it all looks pretty inconclusive due to lack of significance, but horrendous if one happens to be caught up in it.
Some of those fuel pipe designs are hilariously bad – or would be…
I would suspect that a strap-on (!) has a bit more opportunity to deform or even bugger off down the road, as opposed to being forced to split.
What terrifies me is how close those tanks are to the rear panel; there is NO deformation space before the tank is compromised. Most sensible cars have a few inches of floorpan to ruche up (even funny little Yerpean ones) before the tank is invoked. The Hansa 1100 had a drop-in, with the spare wheel well as the top of the tank (patented), but didn’t look quite as vulnerable. Too few of those made for any statistics, sadly.
It’s a bit like how the spare tire seems to be thrown into the middle of the trunk. Yes, I’ve long condemned the inept trunk design of many US cars.
If that gas tank hazard get a coverage as big as the Pinto gas tank hazard. I wonder if it would have badly damaged much more Ford.
Great follow-up to the previous article! Perhaps we are seeing things too much with our contemporary viewpoint: when the Falcon was designed, seat belts were not even mandatory equipment.. never mind actually being mandatory to use, and the fuel tank was just another unavoidable compromise in the design of what was an extremely successful car
^Exactly. It’s a part of living with an old car. You CAN improve on some of these things and that’s why my 64 Comet will get front disc brakes in the future. Also, putting a sealed bulkhead between the trunk and the passenger compartment is no placebo; there’s a reason why this is required by all racing sanctioning bodies and I may also look at those explo-safe tanks. But ultimately you accept the risk or drive a modern car. I have to say though, I do not remember any horror stories from back in the day about Falcons/Mustangs/Comets/Meteors/Fairlanes bursting into flames on every street corner – it was the Pinto that got the headlines on that front.
So maybe they were no worse than any of their contemporaries.
Old man’s memory: I part-time towed my entire career. I can’t remember Fords ever being fire-traps before the Pinto and with my opinion of all things “henry” I think I would have. Actually, in all of the ugly police tows I did I can’t remember any fires at all. I don’t think they were all that common, just gruesome. I don’t have any numbers, though, just my bad memory.
The Pinto became a national news story because of the MOTHER JONES article (https://www.motherjones.com/politics/1977/09/pinto-madness/) and later the negligent homicide trial. Fires in Mustangs, Falcons, Comets, etc. were certainly in the news, but they were a local news item. For instance, I’m sure New Yorkers in the late ’60s heard about the guy whose ’67 Mustang blew up on the Queensboro bridge (https://www.nytimes.com/1971/10/13/archives/-67-mustang-owner-awarded-400000-for-explosion-burns.html), but that probably wasn’t a headline in Sheboygan or Tacoma, say.
Well, that is certainly a perfect example of what probably everyone here thinks is dangerous (both tank and Ford lawyers). The cigarette lighter is a nice touch. Doesn’t really compare with any other car, though. So many numbers being twisted by so many different people, as so many have pointed out here.
The information super-highway, 24/7, vs. “around the water cooler” (old US term for gossip). Thank you.
P.S. Have you ever wondered why US cars fuel on the left while Europe uses the right?
My parents special ordered a 1965 2+2 Mustang Fastback. First new car they EVER ordered. They sold it after 2 years of ownership due to the constant smell of gasoline fumes in the passenger compartment and in the trunk. And now after all of these years I finally get to understand the root cause of the gasoline smell.
Shame on you FoMoCo!
FWIW, the Lancia Fulvia Coupe has a drop-in tank with the filler tube on the passenger side behind the rear wheel.
The Lotus Elan has a drop in tank, surrounded by fiberglass. I don’t think it matters much that the filler is on the passenger side, in this case.
The lesson here is don’t deviate from industry practice when it comes to fuel tank mounting. At least then you’re all in it together.
Aaron where did you find the information on Ford weight analysis? SAE paper?
I worked in the aerospace industry for a while, there were full time weight and balance engineers.
I have owned two of the Ford cars with drop-in tanks, a 1964 Falcon and a 1966 Shelby GT350 (Mustang). The Falcon never had any issue with the tank. The Shelby had ane problem not addressed, rust. The tank is sealed where it bolts in place, but there is a roughly 1/2″ deep channel around the top of the tank to trunk floor. This can and will get water in from a leaking deck lid gasket or on the fastback Mustang, a leak around the rear window. I kept smelling gas fumes in the Shelby, and noticed that the trunk floor mat was damp with gasoline after a fill up. After removing the mat, I found several rusted through pin holes, tank replacement time! The channel is visible in the molded rubber mat so you can get the idea of where water would settle.
14# is a significant amount of weight reduction, make no mistake .
I was there when all these oldies had floor mounted fuel tanks, yes in bad crashes they spewed gasoline into the trunk and often the passenger compartment .
If you want a super safe automobile, get a Checker .
Picture #13 clearly shows how rust accumulates between the leaves of built up leaf springs, it’s a worthwhile thing to insert Teflon strips , they really make any older leaf spring car ride better and hold the road better too .
‘A’ Model Ford partshaus’ sell these strips at fairly low co$t .
-Nate
I worked in dealer service for both GM and Chrysler. There is nothing worse than being told an obvious problem does not exist. A good example of this was the Chrysler A604 transmission. They were failing left and right, yet we were instructed to downplay the problem by accusing the owners that the were somehow abusing the transmission. The 2.7 V-6 was another example. They blew up with great regularity, but we were told that it was due to a lack of oil changes.
Thank you for chiming in. I fought GM for 14 months over a lemon 1998 Chevy Cheyenne with the 4.3 engine.
It would routinely downshift on flat ground (i lived in Fort Lauderdale!)
One of the dealers handed me the paperwork with the infamous “cannot duplicate customer concerns.”
So I challenged the mechanic (who’d driven 7/10’s of a mile to make his determination)
I asked “what is the computer was bad?”
He answered that doesn’t happen. So I asked what things might set of the CE light?
He said things like a missing gas cap, or a bad coil pack. So I took off the gas cap and unhooked one coil pack. No check engine light!
After that, I went to the Attorney General and they forced GM to buy back my truck!
It’s ridiculous to me that manufactures can take a devil may care attitude with people’s lives by building unsafe vehicles. Oh well
The term “cannot duplicate customer concerns” was used a lot when I was a service advisor. It often came from the manufacturer, like in the case of GM’s infamous lock cylinders on the Cobalt, or the A604 for Chrysler. On the other hand, it also can come from a mechanic, who doesn’t want to lose time looking for an elusive fault. In each case, it is to benefit the people working at the stealership, not the customer.
Lots of interesting gas tank placements in the past. Many trucks had them in the cab!
https://www.cjponyparts.com/resources/c10-gas-tank-relocation?srsltid=AfmBOoqudVrxsK3YQ8q_wfqBJzUfPUcGKsXsyVPwTVME1dJvxN17ZQ7d
I was going to bring up this point, but you beat me to it. With the (possible) exception being that putting the fuel tank in the cab was useful for rust prevention, I can’t think of any other reason that anyone thought that putting the fuel tank inside the cab, right behind the seat, was a good idea! Yet most manufacturers did just that. Hmmm.
I remember hearing the fuel sloshing around behind me in my cousin’s GMC half ton. It was rather disconcerting!
My ’71 C10 had the tank behind the seat. Except for occasional smell, usually right after a fillup, no real concern. If the collision was severe enough to destroy the integrity of the tank, my passengers and myself would have already been crushed to death.
Interesting article and I had previously read articles that in fact, the fuel tank design issue was not just a Pinto issue. It was the law suits that got all the news. I have owned two cars with the rear fuel filler, 1963 T-Bird & 1976 Eldorado. I have always preferred this design because you are not going to drip gas onto the paint when refueling.
There is also a slight mention how manufacturers sometimes do as little as possible when it comes to safety vs cost. I agree that has been historically proven but on the other hand I have experience of over-reaction for safety concerns. Many decades ago I bought five new name brand tires for my auto. Within a hour a front tire blew while exiting an Interstate at low speed. The tire dealership & the tire manufacturer both said I must have hit a road hazard, not their issue. Not to be brushed off, I contacted the correct federal office, they were interested and even paid for me to ship them the tire. The end result was at least one batch of these tires were recalled. it was a faulty issue with the tire. On the other hand, back about 2012, GM had a recall on the switch-blade key fobs used on a number of vehicles. The issue was if you kick your knee high enough to hit the fob it could cut off the engine. I have a 2011 Camaro, I tried high kicking my leg up and sure enough after a number of try’s I could cut the ignition switch to off, but it took effort. I can not imagine why someone when driving would kick their leg/knee up high enough to hit the fob. The real issue was the design of the column mounted ignition switch but the cheap fix was to recall all the switch-blade key fobs, cut them up so the key did not pop out of the fob by the push of a button, just another key with a dangling fob. Oh My Gosh, the uproar on the Camaro Gen-5 web forums! I remember the day I took delivery of my new 2011 Camaro and the sales associate was pointing out some features that started with that wonderful switch-blade key fob. Push this little icon on the fob the car will auto-start from a distance. Push this little icon on the fob and the alarm will sound if I am being attacked by zombies. Push this little button on the fob and out pops the ignition key, how cool was that! At the time of the fob recall I was living in Canada where I bought the Camaro and had received five key fob recall notices from GM. A few years had passed and I realized when I retired I would move back to the States with my Camaro and I couldn’t import the car to the US until I had written documentation from GM Canada all recalls had been satisfied. So I took only one of my two key fobs back to the dealership so they could eviscerate my fob, recall satisfied. As I mentioned the design issue was with the column ignition switch but the cheap fix was the switch-blade key fob. A few months ago I was going to use my housemates 2016 Subaru Crosstrek and I left the engine running as it hadn’t been driven in weeks. It has an ignition key with the dangling fob. Getting into the car, somehow my knee hit the dangling fob, the engine cut off. You see were this is going? Even with an ignition key with a dangling fob you can raise your knee high enough, hit the dangling fob and still cut off the engine.
Sorry for the long story. My entire key fob issue is to point out auto manufactures do stupid things to save a few dollars and in this case it was all about the design of the ignition switch and not the key fobs. My end note is that in Canada there is a class action suit against GM that has been winding its way through the courts for years over the issue of the GM recall of key fobs. I am part of that class action because I bought my car in Canada when I lived in Canada. If the class action against GM gets resolved, what am I going to get…a few Canadian dollars that would hardly cover the cost of the mailing checks. This issue was with the poor ignition switch design and not the key fob design but it was the quick and cheap way for GM thinking they could avoid lawsuits, yet not resolving the problem.
I think the biggest weakness of the design is that IF the top half of the tank ruptures from a rear end collision, the fuel is going to be forced out (under much pressure) inside the body instead of under it, with little besides the upholstery of the back seat between you and the spraying gasoline.
It is true that tanks inside the passenger compartment were normal in pickups for decades, but at least the location was better protected from impact based on its height and central location.
Filler pipes were usually (at least in my experience) connected to the tank with a pliable section of hose, which would likely tear well before the steel pipe.
But gasoline is dangerous stuff and even the best containment systems can fail given the right conditions. Diesel fuel is far, far less volatile.
Yeah, I think the way it’s attached creates the possibility of a rear impact essentially tearing open the tank like the top off a pull-tab can. Figuring out the practical likelihood of that would happening probably require some kind of kinematic modeling, but there were certainly incidents of that occurring. As the Pinto demonstrated, having the under-floor tank be rammed hard into the axle bolts wasn’t any better.
Fast forward to the ’80s when Ford put a dummy transfer case in 2wd Bronco IIs for some strange reason. You have to see one to actually believe it.
Wasn’t that for better side to side weight distribution? The early 1980s GM FWD V8 powered cars had a plate under the drivers seat because the transaxle arrangement meant that the passenger side of the car was IIRC, about 120 lbs more than the drivers side.
To be honest I never gave much attention to the fact that my trunk floor was my gas tank in my 68 Cougar. Still don’t nor in my 68 Mustang. I don’t have the steel cover that attaches to the back sit from inside the trunk. Although I did think of making my own steel cover for the top of the tank decades ago and then went nah. I have seen that idea where it looks like the top of your tank.
I own a ’66 Mustang and formerly owned a ’67 and a ’62 Fairlane. I cannot remember if the Fairlane had the rubber section in the fuel filler, but of course both of the Mustangs did. I have always thought it was a ridiculous idea. About 10 years ago I kept noticing gasoline smell in the trunk. The tank has no rust so I replaced the rubber section and solved the problem. The old one showed no signs of deterioration but obviously was letting fumes leak out. I got rear ended in my Fairlane which did a number on the gas tank but it just needed replacing with no leaks. I had just bought the car which was 4 years old at the time. I think I might have been a little worried if I had known how the tank was mounted.
I am really enjoying these deep dives on how cars were designed and built.
I was a bit surprised by the fuel filler pipe on the Duster, for the 1967 VE Valiant, Chrysler Oz curved the pipe down and flattened the lower part so it was level with the trunk floor.
Maybe a bit safer, but it was a lot more convenient.
Forgot pic.
So, as one who has mostly played with BMWs, late 60s to late 80’s for the past few decades, I’ve got a question. They used a similar, but different tank. Structurally it would appear to be the same, but the obvious isn’t always. They bolted tanks in from the bottom, hanging on half a dozen or so bolts. All from the bottom. But the top of the tank was the bottom of the trunk, well, excepting the 1/8 to 3/16″ trim plywood, or particle board, along with some carpeting between the tank and the trunk. In other words, take out the trim and the top of the tank is the bottom of the trunk. But bolted from underneath. Is there any difference?
Part of the trunk or not, the more modern trend of under the back seat is such an incredibly better idea I don’t know why it wasn’t used decades earlier.
“If Ford had gone with Proposal B for the Falcon gas tank, putting it under the trunk,”
Just want to mention, Unless I’m mistaken, according to the sketch, “Proposal B” was the DROP in Tank, not the “Under trunk Tank”.
Am I missing something?
Oops, that was an editorial error — that should have been “Proposal A.”
I’m here to help. 😉
I can’t believe that 70 Falcon sold for $4700.
Seems like a deal even for 2022.
Since I did my apprenticeship at a Holden dealer, I rarely soiled my hands on Fords. My only memory of the drop in tank was when one of the old guys was fitting a trailer wiring harness.
He was looking for a easy place to drill a hole to earth the harness. That easy place was the top of the tank, and since it was full, a mini gusher of petrol shot upwards.
Fortunately he was using an air drill, not electric.
Ouch, yes!
I own a ’64 Fairlane, and I’m almost certain it’s got a conventionally hung gas tank and trunk floor (62-65 would all be the same, either way). I could be wrong – I haven’t looked at it in a long time. Regardless, the fuel tank was always something that concerned me. If I had to guess, I’d say the Falcon design was more rupture-prone in an accident. Slightly. I’d think a hit that deforms the rear end would seem more likely to deform a tank bolted in than one that’s strapped and will just bend or break the straps.
Despite my suspicion on that, I don’t see it as particularly “defective,” not any more than any number of choices made back then that wouldn’t be made today. I’d be really curious if there were any useful statistics, but my suspicion is that you’d find all cars with under-trunk gas tanks to be more fire-prone, with the trunk floor type only making the situation marginally worse. Whether there was a difference or not, there were more than enough horror stories for lawyers to latch onto the distinctive design and find some experts to pin the blame. Again, hard to be sure, but the vast majority of Falcon/Mustang/Comet injuries and fatalities were the result of something other than fire.
Ultimately, the exposed, under-trunk gas tank (however it’s mounted) is enough of a liability that when I get around to restoring my Fairlane, the gas tank will be relocated. It was long ago retrofitted with three-point belts; not that I needed convincing, but my grandma in particular didn’t want me to chance it. While I certainly bemoan the loss of life and limb to the lack of safety built into such cars, I find the blame falls a little heavily on manufacturers, considering consumer sentiment was a big part of that mix. When seat belts became mandatory, many simply didn’t use them. In ’55 and ’56, Ford introduced a variety of safety features (some optional) and marketed on those. And they were handily outsold by Chevrolet in reward, so all that was quickly forgotten. It’s easy to question the choices made, and to envision a world where one of the big three decided to sell safer cars and was rewarded, but I could easily see Ford or Chrysler folding under because of committing to higher costs the market wasn’t interested in bearing at the time. No doubt the big three do deserve some blame for working to undermine safety initiatives and downplay the risks, but this doesn’t even compare to the Pinto, and even that was pretty overblown. I’m sure GM and Chrysler loved it, but knew their stuff was no better and they could be next.