Curbside Comparison: 2007 Mercury Grand Marquis vs 1991 Cadillac Sedan DeVille

This competition could be called the “Old Off” given the cars at hand – it’s been 7 or so months since I purchased the 91 deVille, so I figured now would be a good time to write the comparison JP Cavanaugh requested. Both are (supposedly) full size 6 passenger vehicles with V8 power, softly sprung suspensions, along with plenty of plastic wood and chrome for a true Brougham touch. So let’s break it down into various categories, starting first with…


OK, you can stop laughing now. Most people who bought these cars weren’t interested in outrunning Bimmers, however they did like the instant torque and bragging rights of a V8, fuel economy be damned. The Cadillac has the final evolution of the much maligned HT4100 aluminum V8, enlarged to 4.9L and bestowed port fuel injection to give it some real oomph with 200 hp @4100 RPM and 275 lb-ft of torque @3000 RPM.  The Mercury has the beloved Modular  4.6 L 2 valve mill, making 224 HP @4,750 rpm and 272 lb-ft for torque @3,500 RPM.

Despite having more horsepower, the Mercury is slower off the line – I’m sure gearing as well as the torque curve has something to do with it, but it is noticeable. On the highway both can hustle without issue, but the drive by wire nature of the Mercury means there is lag from when I push the petal down to when it downshifts whereas the Caddy responds instantly. There is a hit for that lovely instant gratification – the Caddy averages 15.7 MPG around town vs 21 for the Mercury…and Premium unleaded at that.

He kept riding my bumper…and then when he tried to pass found that he couldn’t!

Neither car is happy in the twisties, but the live rear axle in the Mercury is especially twitchy unless you have really good rubber. The ass end of the Mercury likes to come unglued when it rains on curvy ramps, and in the snow it is awful even with the traction control. The independent rear suspension of the Caddy makes all the difference – it is much happier taking curves and I never feel like it is dangerous in inclement weather. When I feel more secure in a Suburban than the Mercury…that says something.

I did replace the air ride in the Caddy with conventional springs – with no reduction in ride quality or handling. One less thing to worry about, plus I rarely have 3 other people and their luggage in the car.

So even with the less than stellar mileage, the Caddy takes the performance category for the better handling and instant throttle response.


This isn’t quite an apples to apples comparison given the trim level difference – my particular deVille has only one option on it, the Delco Bose Gold sound system. Aside from that it has a manual passenger seat, Primavera cloth interior, no lighted vanity mirrors, no locking fuel filler door, and no trunk pulldown assist. But it does have Electronic Climate Control, power driver seat (manual recline), power mirrors, rear defroster, and rear vents for heat & a/c. Both have loads of plastic wood trim, analog instruments, and are tan in color. However, the Cadillac feels much nicer to the touch – the Mercury has hard, cheap feeling plastic surfaces everywhere that look like the tarted up Crown Vic bits they are.

The Grand Marquis does have very comfy heated leather seats, and a power passenger recliner. As far as roominess goes, the front seats of both feel about the same, with the Cadillac having a more useful clamshell armrest for storage & cupholder, with the Mercury’s cupholders placed on the dash in front of the EATC. The rear however is where the Caddy shines – with no big driveshaft tunnel, wider doors, and a bit more legroom, there is no back seat penalty. Shoulder room would be tight in both cars trying to fit six in, but would be a bit more comfortable in the Merc side by side. Getting in and out is easier in the Mercury since the car isn’t as low to the ground, but once inside I like the Caddy a bit more.

Trunk space is a clear winner for the Mercury – despite all the Mafia jokes, the FWD C body deVille is not a “six body trunk”…four at best. Load height is better with the Caddy, but the deep well trunk on the Grand Marquis will allow you to go into the moving business if desired.

For the heated seats and trunk space, the Mercury gets the nod in interior comfort – but only slightly.



Ford Quality Control apparently took the day off when this car rolled down the line – the 28 year old paint on the Caddy has held up perfectly while the paint is peeling like crazy on the Mercury. For the first 11 years of its life, the Merc was garaged or under a car port, washed regularly, and still this happens. Aside from that, I like the exterior styling of both – even if the “Whale” styling of the Mercury was getting long in the tooth.

The big chrome grill, wide tail lights, sidemarker lamps, and curves work on a full size car. The Caddy matches it with chrome and then some with the metal pushbutton door handles, finned taillights, and powerdome hood. Chuck Jordan worked magic on the 1989 redesign and these cars finally said Cadillac again instead of “740 Brougham.” Hearsay to some Broughamites on here, but I like the aluminum rims on both cars vs the wire wheel covers. Much cleaner appearance, especially since neither car has the perquisite vinyl top for the full Brougham look. For the paint issues, and the tail finlets, the Caddy wins for exterior.

In the words of Sir Mix A Lot – Baby Got Back!


1991 was the second year all deVille’s came equipped with a drivers side airbag, and the first that anti-lock brakes became standard (a fact that your brake pedal will remind you of!). Aside from that, rear outboard lap and shoulder belts were standard with only the middle passenger lap belt only. The Mercury has driver and passenger airbags, along with side impact airbags for the front passengers, lap and shoulder belts for all three rear passengers, the LATCH system for car seats, as well as ABS and traction control. So hands down, the Mercury is a safer car to be in – unless it’s snowing/raining and you have bad tires.


Giving the General credit where credit is due, they did put some lovely tech into the 1991 deVille – you could get it with keyless entry, it came with a standard central door locking system, an Oil Life monitor was standard equipment, the Electronic Climate Control was still ahead of what was on most other cars, and the six speaker Delco-Bose Gold speaker system still sounds great after all these years. I did replace the head unit with a modern Sony HD Radio one however – as much as it pained me to yank out the AM Stereo unit, having HD and the ability to play audio from my iPhone is higher up on the priorities list. And the power antenna in the rear pulls in signals much better than the in glass affair in the Mercury – not to mention the electrical system is quieter in the Caddy, which is important for AM listening (for me at least). But the Mercury has steering wheel controls for the audio system & the EATC – not to mention the keyless entry keypad, adjustable pedals, and the nifty message center that does what the “Fuel Data Center” in the Caddy does, plus all the usual low washer fluid/change oil/door ajar messages. So the Mercury wins the tech category – but given the 17 year difference, it should! The big difference being the adjustable pedals, door keypad, and traction control.


This one is a tough one given the age difference – all I have had to do to the Mercury is change the oil and some light bulbs. The Caddy however when I bought it I immediately drove it to the shop for a new brake master cylinder. Other repairs in the 7 months of ownership include the new rear shocks, new water pump, new battery, and it also needs a new A/C compressor. For a 28 year old car – not bad! But if there is a “Cockroach of The Road,” it is the Panther platform. Especially the 3rd gen with everything sorted out – no intake manifold cracking, no valve seal oil burning, and the tough as nails 4R75E transmission backing it up.

Great car, awful paint

The 4.9 in the Caddy is much MUCH improved over the 4100, but I still throw in those GM cooling system seal tabs as preventative maintenance when the fluid is flushed. I’m convinced that Cadillac didn’t put the 4.5/4.9 in the Brougham from ’88 on because they were worried about fleet usage, despite the 307 Olds only giving barely acceptable performance levels pushing around that much heft. The Hydramatic 4T60E is durable enough in these cars, and does shift smoother than the 4R75E – GM could still get it right when they wanted to. Even with the relatively trouble free miles of the Caddy, the 4.9 still worries me a bit so the Mercury gets the durability trophy. Just as long as the primer holds off the rust.

Final Thoughts

Both cars have zero squeaks or rattles – impressive given the body on frame nature of the Grand Marquis, both are wonderful road trip cars, and both excel at isolating you from harsh roads (thanks PennDOT!). But that being said, the Mercury really is not “luxury” – yes, the steering wheel has “wood”…but the dash looks and feels cheap. I suppose they didn’t want to make it too nice and encroach on Lincoln Town Car territory, but even still – the car has solid bones but Ford just cheapened the hell out of it post 1998, especially by 2007. The rear doors have the cutout for ash trays, but no ashtray – little cues like that.

But there is one more thing that has me driving the Mercury less and the Caddy more – my Grandmother. Grandma Z has dementia, and as of late it has been getting worse. With that, she forgets that she gave me the car and has been calling me asking for it back. Trying to reason with her just ends up getting her upset, so I’ve taken to telling her that it’s in the shop. She also at times believes that she still has Pappy Ron’s 1995 S-10 – that was sold back in 2010.

Summer of 1995 in Juniata Terrace – you can see the front of their 1992 88 Royale

So it adds to my general stress and anxiety driving the car – and with that I have decided to sell the car. I didn’t have these feelings with my first two vehicles that I inherited from my Pap – I supposed because his death was sudden rather than having to watch the long fade into darkness, and in the case of the 84 Sedan deVille, it stayed in the family until the 4100 gave out sometime in 2008. But whatever I get from selling the car will go to her, as she now requires someone to help out at home – not cheap.


Have no fear – as I still have the need for a RWD BOF land yacht in my life. Here it is for a future article. I take delivery this summer if all goes according to plan.