View Full Version : gas mileage

07-18-2001, 08:20 PM
My first post yippeee!
I have a '67 shorty witha 250 in it. I get 15 or so under 45 but over it shoots down fast to 10. I figured out my timing isn't advancing enough..any cool electronic replacements? What should the mileage be for a 3 spd? What about a 4 spd conversion? damn I love my hippo....thanks V

07-18-2001, 11:51 PM
Welcome Victor. There is a good and simple electronic ignition. Pertronix Ignitor it cost about 75 bucks on the west coast. It made an improvment on my 250. And no parts outside the distributor. The part number
is 1162A.
And take a look at the topic called
westcoast2. We'd like to see you come to our ralley on Aug. 4 in Roseburg Oregon.
Good Luck,

07-19-2001, 04:30 AM

Glad to see you on this site. This is a good place for information with really great people. (Me too.) http://www.vcvc.org/ubb/smile.gif

Gas mileage should be the same or close with either the three speed or the four speed. Usually, the top gears have the same ratios and make very little difference. If you want good gas mileage, keep your foot out of it and hold the speed down. Once you pass 50/55 the mileage goes way down.



07-20-2001, 01:36 AM
HI guys!
Thanks for the info on the ignition, that should help alot. As for keeping my foot light I usually do....I had a 230 in it before that did better (go figure) it spun a main at 203k so I thought " that was a good engine..bigger is better?" Not that I can see so far, but I really love that van.."The Hippo" its my daily driver when its too wet for my bike..is Roseburg very near portland? Is it a big too do? Do they have a prize for ugliest van? Anyway, thanks for the help
have fun,

07-22-2001, 11:27 PM

tha's pretty deplorable gas maliage...i should KNOW I get 10 MPG city or hiway

I am running a 350 4 barrle and a 456 rear end ina 6000 lb van though.....you should be able to get high teens in with the 6.

If oyu do a lot of hiway.....consider taller rear end gears......they would pay for them selves quick in gas


Duane 70gmc
07-22-2001, 11:56 PM
Just curious, what kind of mileage should I be able to get on the freeway. With a fairly tight 307 and a glide, is 18mpg to 20mpg unrealistic. Planning a trip from Detroit to Reno and want to do a few calculations before I go. I will do some driving to test the milage before I go, but I'm looking to find out if the mileage I'm looking for is unrealistic or not. Not sure of the gear ratio though.

Duane ... Proud owner of a 1970 GMC 108" V-8 Vintage Van
Any ? Email:
VCVC Rules

07-23-2001, 08:02 AM
Thanks for the feed back yegg. I have been thinking perhaps my gearing is an issue..I get into 3rd at 30 mph and go from there. I just don't know all that much about gearing. I guess the rear end is the easiestway to make a small change? maybe posi trac? any recommendations? Thanks V

07-27-2001, 12:56 AM
That's right the rear end is probably the easiest way to get taller gears (numnerical higher).

It's apretty standard job for any good drivline mecahinic.....I would not recomend it for a first timer to do your self......check around for prices in your area.....you almost ahve to go in as most shops don;t know what axel you have in the old van


07-27-2001, 08:03 PM
well, another way to "cheat" with the rear-end gearing without replacing them is to install taller tires, making the wheels have to rotate less at a given speed than a smaller tire, lowering your engine revs and subsequently saving gas

I have the math formulas somewhere to compute what your effective rear-end ratios are depending on your tire height, and can post 'em when I'm on next, though you could probably find a site somewhere that has 'em before I get back on...

08-04-2001, 02:10 PM
As the former owner of several vintage Dodge (A100) vans all (except one) of which were 225 slant 6 / 3-tree powered, I seem to recall fuel economy on the order of the low-mid teens. The factory 318 V8 powered van I owned for a short time (prior, that is, to its throwing a rod through the oil pan) averaged lower fuel economy, more on the order of 10 to 12 on a good day miles per. And you didn't want to seriously even consider running at 75-80 mph speeds typical of interstate travel these days for fear of 1) Blowing up your engine. 2) Loosing control and killing yourself or someone else or if neither of those things happened 3) Having the already "fairforitsdaybutdamnhardtohandlenow"fuel economy fall quickly even into the single digit realm.

In returning after a near 15 year hiatus to the wonderful world of vintage, "early", or as I always refered to them in the past Party-vans, and being particularly enthralled this time around with the origional Chevys...I am interested in your input, comments and experiences on the topic of vintage Chevy van fuel economy, both 6s and V8s, 3-trees and automatics. I would expect chevy 6 cyl. gas mileage to be roughly comparable to the Dodge slant 6, but am curious as well. Has anyone managed 6 cyl. mileage significantly above the mid teens?

08-06-2001, 12:37 AM