CC Meet-Up Outtake: Back from Portland With Happy Memories and a Lot More Gas in the Tank of the Van Than Expected

I had a great weekend in Portland. The Shape of Speed exhibit at the Portland Museum of Art was simply sublime. I will write it up along with some decent pictures thanks to PDXMike’s new camera he’s holding here. Next to him is CC reader Teddy and Keely. And we’ve got some pictures from the Vintage Race Meet at Portland Raceway that we’ll post too. A couple of other CC readers showed up for that and lunch afterwards. A good time was had by all.

It was the maiden trip for my van as a camper, even though it’s not really finished. But I wanted to get a feel for it on the road to make sure the solar panel adhered to the roof only with 3M VHB tape was not going to blow away, to sleep in it, and also to get a sense of what kind of mileage it would get. I was pleasantly surprised.

before the conversion

On the trip home from picking it up in Kellogg, Idaho, I only got about 16mpg due to ferocious headwinds the whole way. In a big tall van, that hurts. And since then I’ve only been driving it around town and haven’t even bothered to keep track. But the trip to Portland and back on I-5, which is mostly level and on a weekend without winds made it a good time to get a sense of what it can do.

I tried several different speeds using the cruise control (which I used the whole way except for a few moments), to see what the results were on the instant-read mpg indicator. Pretty soon I settled on 68-69mph (speed limit is 65). That put me in the right lane with the trucks, not where I typically spend my time in our cars. With the ’77 Dodge Chinook, I normally cruised at 64-65 mph, and over all the years and 25k miles we used it, it consistently averaged 11mpg. But with the Promaster (a 159″ wheelbase high roof 2500 model) I was seeing 20-22+ mpg on the instant read out. Whoa! I seriously did not expect that with such a big van, the gas engine (3.6 V6 and 6 speed automatic) and the solar panel and MaxxiFan on the roof.

I didn’t drive it much in Portland, just to Mike’s house where I spent the night in his driveway (Thanks Lily for the wonderful breakfast!).

On the way home I saw similar results, although I did briefly draft a semi doing 70 at various distances to get a sense of how that affected instant mpg It increased from about 22 up to over 30, depending on how close I got. I remember seeing 35-37 for a short bit, but I was pretty close. The big fuel savings in platooning will be a boon when cars and trucks can do so autonomously. At a reasonably safe distance, it was about 24-25mpg. The effect tapers down, but is noticeable quite a ways back, as the semi leaves a pretty long reduced-pressure wake in its tail.

The final tally for the roughly 250 mile round trip can be seen above: 21.1 mpg (indicated). Obviously that might not be exactly what it is based on actual usage as monitored by a fill-up, but in any case, it’s quite a bit better than expected. I was anticipating about 17-18 mpg under these circumstance.

So I came home with a half tank of gas and a full tank of memories of a lovely weekend. Thanks Mike for your hospitality, and suggesting it in the first place. Now to write up that exhibit….