MPG w/35's, 4.56's, 700r & 350eng?

[muzzfactor]

Hey Guys, I'm having alot of trouble figuring out what kind of mileage I'm getting with this setup. I know my speedo is off quite a bit, but I think if I'm going around 75 by the speedo I think I'm close to actually 68. Does this sound right? My tank is 15gal and right now I'm getting about 130 miles to a tank which is very concerning considering the discrepancy with the speedo. Any input is greatly appreciated. Thanks.

 

[imiceman44]

Hey Guys, I'm having alot of trouble figuring out what kind of mileage I'm getting with this setup. I know my speedo is off quite a bit, but I think if I'm going around 75 by the speedo I think I'm close to actually 68. Does this sound right? My tank is 15gal and right now I'm getting about 130 miles to a tank which is very concerning considering the discrepancy with the speedo. Any input is greatly appreciated. Thanks.

I have a very accurate way for finding my real miles, I use a GPS which gives me exact miles, if you have one or know a friend you can borrow it from for a couple of days.

 

[4X4HIGH]

FWIW i'm running the same set-up only i have a 31 gallong tank and i can go about 230 miles on a tank and that is usually on about 27-28 gallons on fill up so i'm only getting around 8mpg give or take depending on if i'm only city or some hiway driving. Now keep in mind i have a pretty hot engine in my rig.

 

[StevoandaRedK5]

Now keep in mind i have a pretty hot engine in my rig.

From what I've read about it, this may be an understatement. You build some sweet engines

 

[chevyuser74]

best mileage i ever got was 15.1mpg usually get around 13mpg 350tbi/700r4/4.56s/35s

 

[frankin5]

13 with carb on long trips with air running.

 

[muzzfactor]

Thanks for all the info guys, I think I'm in about the 8-10mpg range. Looks like I might have to turn this baby into a weekend warrior instead of a daily driver.

 

[throttleissues]

If it's stock engine, then why don't you just get it running better and bring up your mileage. My K20 gets 9mpg highway, but it's carbureted 350, TH350, 4.56, and 36X13.50 IROK bias tires. Your truck should be kicking mine's ass in the mileage department.

 

[BUDDY]

Just to throw in my most recent experience with my most recent blazer. See the sig for specs, but I drove it up from Lake Havasu City & then around town for work, filled up when there was 290 miles on the odometer & put in 26 gallons. That almost equals 11 mpg!! I was STOKED, because I was hoping for 8, but I'll take this all day long!!

Also, the speedo is within 2-3 mph compared to GPS so the previous owner did me alright in regard to he speedo correction procedure.

Later,
Buddy

 

[oakknight]

I have a 1989 Blazer with 350 TBI 700r4 4.56 gears and 35 in pro comp MT. I have put in a dakota digital dash and calibrated the speedo. the engine is stock , but i have put a chip , tb spacer and K&N extreme air filter , Electric fan setup and Headers with 2.5 dual exhaust. I get 8-9 so far , but only run one tank thru it. Was kinda romping it with the new gears .. had 3.0 somethings in it before (3/4 ton axles out of a 79 k 20)