Ive been trying to figure out my mileage,and is doesn't look good.Ive come up with exactly 10 miles per gallon.Is that about average with my tire size.35 in MT baha claws,my motor is 5.7L with 91,000 orig. miles, new plugs, wires, fuel pump,air cleaner,oil change,rebuilt TB,TB spacer.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Is my gas mileage average?
- Thread starter starfish
- Start date
Probably. You don't mention gears, and with those tires on stock gears you are bogging your motor Down.
Jester1
1/2 ton status
You should be doing a little better than that. My '90 454 gets better, although you are slinging 35's check your gearing in the axles may be losing some there.
Are you taking into account the fact that your speedo is now off because of the increased tire size? Your odometer won't read correctly and if you go by that, you will think you have worse mileage.
Your tire size divided by stock tire size (about 31). Multiply that by your miles traveled to get the corrected distance. Then divide by the amount of gallons used. My m1009 with 37s and stock gearing gets around 18mpg but thats with a 6.2l diesel
Your tire size divided by stock tire size (about 31). Multiply that by your miles traveled to get the corrected distance. Then divide by the amount of gallons used. My m1009 with 37s and stock gearing gets around 18mpg but thats with a 6.2l diesel
Stomis
Professional Amateur
Hmmm my "trazer" with a TBI 350/sm465/3.73s and 36in TSL radials got 15mpg on the highway at 55mph.
I would think you could do better.
I would think you could do better.
K5dreamer
1/2 ton status
whats your complete drive train setup?
vehicle model - ?
year - ?
engine - 5.7 engine TBI?
transmission - ?
axle gear ratio - ?
tire size - 35in
is this highway mileage, city mileage, or combined?
are you towing, plowing, hauling heavy loads?
be honest about your drivng habits, are you a lead foot? I know i picked up significant mileage just changing my driving habits in my daily commute (an extra 100-150 miles per tank in my diesel jetta)
vehicle model - ?
year - ?
engine - 5.7 engine TBI?
transmission - ?
axle gear ratio - ?
tire size - 35in
is this highway mileage, city mileage, or combined?
are you towing, plowing, hauling heavy loads?
be honest about your drivng habits, are you a lead foot? I know i picked up significant mileage just changing my driving habits in my daily commute (an extra 100-150 miles per tank in my diesel jetta)
CGT80
1/2 ton status
88 K5 new-stock 5.7tbi/700r4/208/4.88/315-75/r16=10mpg
79 C20 built 406sbc/th-400 and gearvendors/4.10/33-12.50=10mpg
79 C20 built 406sbc/th-400 and gearvendors/4.10/33-12.50=10mpg
1987 blazer silveraldo,motor is 5.7L TBI, stock and orig 91,000 miles .auto trans(stock),373 gears(stock),only mods are 4" sus,3' bod lift and 35" MT baha claws.I know my speedo is alittle off(if Im going 40 its really48).So with the speedo being off its around 12?
CGT80
1/2 ton status
Looks like you are probably getting 12 mpg at best. Somehow I just don't see these old trucks getting to the mid teens for mileage unless they are diesel or just really babied and in mostly stock trim. My mom's 2005 Silverado 1/2 ton 5.3L 4 door, short bed has never done better than 16 mpg. That is with a more aerodynamic body, lighter weight components, stock height, and a late model computer controlled engine with more power than the old 5.7's.
Changing my gearing to 4.88 helped with around town driving and puts me at 2300rpm or so at 65mph, but it didn't seem to effect fuel mileage much. I think I recall hearing that people with the 3/4 ton trucks with the 8.1L only got 12-14 mpg. I wonder if any of the newer trucks have multi-displacement engines to help with mileage.
Changing my gearing to 4.88 helped with around town driving and puts me at 2300rpm or so at 65mph, but it didn't seem to effect fuel mileage much. I think I recall hearing that people with the 3/4 ton trucks with the 8.1L only got 12-14 mpg. I wonder if any of the newer trucks have multi-displacement engines to help with mileage.
