The Stovebolt Site Forums The Shop Area Engine Shop I know I know another mpg post. 12 mpg average?

1959 apache fleet with a solid running 235. Original carb, oil filter and four speed tranny. 338 rear gear kit from Patrick's. no frills (ac etc) and an average of 12 mpg in town or on the highway. Not complaining just wondering if this is about average or am I missing something I am unaware of to improve the mpg? Thanks in advance for any thoughts offered.

for starters, check your odometer, if you didn't when you swapped the rear gears, then skip using the granny gear and keep a light foot, that'd be about normal with the original 3.90 rear, should do better on the highway unless you're trying to run high speeds

Bill

Well my foot is heavy and I do freeway speeds of 75 so likely it's just driver use. Anyone use a t5 with 338 rear gears? I gather from reading on here the t5 is an option to increase mileage and it seems a swap I'm up for but not sure with the new gearing if that's still a good option.

Make sure the power valve port on the base is not blocked by the base gasket.
Also make sure your vacuum advance is working.

Hadn't thought about the base gasket. I'll give that a look this weekend. Thanks!

I have a T5 in my '59, was told to leave the 3.90 I had because it fits the 5th overdrive gear very well. Someone else might chime in, but I think the 338 you have now is to high a rear for a T5 and you won't have the power you need when shifting into 5th.

Depending on your terrain the V6 T5 may be OK.
With a 3.38 diff the 4 cyl T5 might work better. They only have a 10 percent over and a lower first gear.

I could never believe the Chevy cars in the magazine back at the time claiming 23 mpg in Mobile Mileage tests..... Doesn't seem possible. My 1953 1/2 ton with 4 speed (granny), 235 and stock 4:11 would usually give a flat 14-15 mpg.....

John

I can get 17 to 20 mpg with my '51 Deluxe, powerglide 235, rochester B. I definitely have to keep my foot out of it, though. I can get real close to 20 at a steady 55 mph

Yea I'm thinking it's just my foot and want to drive it like its stolen! Just so much fun once everything's dialed in to drive and regardless the milage every once in a while I just gotta ask others. Thanks everyone!

I get 18-20 on the highway at 65mph. 261 cu.in. .060,howards cam from patricks,fenton headers duals out the back and holley/weber carb from Langdons stovebolt. 3.90 rear end. Truck runs great just a little flat in mid range.