TBI 350 Suburban MPG, whats everyone get????

[1988 GMC 355]

I never do enough highway driving but mixed driving I get about 14 and I never drive easy. Usually on the freeway I run about 75mph also. I only run premium shell fuel and Ive done some timing adjustments. Its not great but for the way I drive its better than the 10mpg it started off with!

your 3" true dual arent helping your MPG


you need 2.25" true duals at biggest

[Old88]

94 Burb with a magnaflow cat-back / 3.73's
12/14 city 17/18 mpg @ 70
After E10 was mandated in Florida
10/12.5 city, the best I can get on the road is 16 mpg now.

[Force_Fed]

I have a '89 V2500 and I get around 14 MPG w/ or w/o A/C running. Everything engine and exhaust is stock. That's also with 3.42 gears and 265/75/R16.

[BlacK20]

I have a '89 V2500 and I get around 14 MPG w/ or w/o A/C running. Everything engine and exhaust is stock. That's also with 3.42 gears and 265/75/R16.

Thats cool and all, but why bump a 1.5 year old thread?

[WMBigs]

87, 3/4 ton, 4wd, 4 speed manual, 3.73 gears, 250000 miles all stock.
Best tank was 14.5, typical is 12-13. My wife was in a hurry driving ~85 and pulled it down to 9.
We don't drive it much.

[survivorcamaro]

yes i know this is an old thread but all the info we can get, the better. i've got a 94 burb 4x4 with 232,000 miles on her and around town i 10-12mpgs and on the highway i can get up to 15-16 and very rarely 18mpgs. all stock.

[winfred]

when i got my 91 v2500 4x4 squareburb with 3.73s 4l80e and 285/75/16s it got 10 combined (speedo/odo very accurate) on my fairly consistent drive cycle, headers/46mm tb and 2.5" y-pipe into 3" added around 1 to that, new temp sensor added maybe another half but i don't have enough tanks through it to call it absolute on that half but its happier. haven't road tripped it yet but the local loop is sneaking up on 12, i have a plenum oil leak that i am going to fix soon and while the intake is off i am going back on with a holly projection intake that looks a lot like the edelbrock tbi intake for over 100 less at the price i got it for, hoping that perks it up a little. wish i could get real gas instead of watered down crap to see what it would get on that, my supercharged hotrod bmw absolutely hates ethanol, i loose 2-4 mpg when i get a juicy tank and screws with the tune a little

[the 73 beast]

91 3/4 ton 4wd v2500 suburban 5.7 tbi 4l80-e 3.73, 4" suspension lift, 33" tires, 3" single magaflow exhaust, gm crate engine 33,000 miles ago, old engine got 9.5 mpg city,13 mpg hwy at 75 mpg, new engine get 8.5 city and hwy. Sucks but still replacing parts for emissions,etc.

[the 73 beast]

91 3/4 ton 4wd v2500 suburban 5.7 tbi 4l80-e 3.73, 4" suspension lift, 33" tires, 3" single magaflow exhaust, gm crate engine 33,000 miles ago, old engine got 9.5 mpg city,13 mpg hwy at 75 mpg, new engine get 8.5 city and hwy. Sucks but still replacing parts for emissions,etc. Using 89 grade gas.

[Sparkee]

95 K1500 Suburban, 350 TBI, 176,000 miles, 3.73 gears, stock sized 245/75R16 tires, some air cleaner mods and the cat was gone when I got it. With a mix of city and highway I typically get 13-14 mpg, running 87 octane. I haven't taken it on a road trip yet to see what she'll do on the highway.

[Emersonsdad]

'87 V2500 Burb, 350 TBI, 208,000 miles, 4.56 gears, 37/12.50/20 tires. I'm afraid to figure it out. Let's just say I hope I'm getting 8 mpg.....

[92chevy4x4]

My 92 eclb 4x4 is getting 9mpg lol

[winfred]

makes me feel better knocking on 12

My 92 eclb 4x4 is getting 9mpg lol

[Srabai47]

1994 262ci gets 19.2avg highway with 3.42 gears and a 5speed at 60mph. try 70-80mph and itll drop to around 12mpg.

[Doober]

The '93 Suburban my parents had way back when would get around 17 highway, not sure around town.

[Dryheat]

94 TBI 350 all stock 265/75/16 reg gas highway and city mix 17MPG. I drive like a old man