Detri Mental
Registered Member
I have the exact same drivetrain in my 90 K5 as crawlin does and I can verify, 25 mpg is accurate.
I got 21.3 mpg pulling a trailer with an ATV and a bunch of gear across mixed roads from 4 lane highways to dirt.
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.
MPG Thread, curiosity
- Thread starter sled_dog
- Start date
I have the exact same drivetrain in my 90 K5 as crawlin does and I can verify, 25 mpg is accurate.
I got 21.3 mpg pulling a trailer with an ATV and a bunch of gear across mixed roads from 4 lane highways to dirt.
gonefishin
1/2 ton status
Yea I bought the carb used and I was planning on building a 400 sbc but I found out that the block I had was bad so I built it this way instead.
Do either of you have pictures/build thread? I'd love to see how well it all fits.
I am happy to get 7.5 mpg
Permanent camper
C-12
E/F 10 speed
3.42:1 gears
11R-24.5 tires that's 43.8"
Top speed is 72mph
Permanent camper
C-12
E/F 10 speed
3.42:1 gears
11R-24.5 tires that's 43.8"
Top speed is 72mph
I had a 79' K5 Blazer and currently have a 78' K5 Blazer, same mileage with different setups:
1979 K5
350/th350/203
3.73/35"BFG MTs/6" lift
quadrajet
12.5 mpg highway
1978 K5
350/th350/203
3.73/33" Pirreli Scorpions/stock lift
Edelbrock 600
12.5 mph highway
...........still nobody posting with TPI
, I'm curious because I'm considering trying TPI on one of my trucks. Seems like the only significant MPG increases are from overdrive and/or Cummins in this thread.
1979 K5
350/th350/203
3.73/35"BFG MTs/6" lift
quadrajet
12.5 mpg highway
1978 K5
350/th350/203
3.73/33" Pirreli Scorpions/stock lift
Edelbrock 600
12.5 mph highway
...........still nobody posting with TPI
, I'm curious because I'm considering trying TPI on one of my trucks. Seems like the only significant MPG increases are from overdrive and/or Cummins in this thread.
I thought we already established that you get 0MPG:
It has actually gotten over 100 when I've run out of gas and coasted.
crashandburn
1/2 ton status
96 Suburban
6.5 Turbo Diesel with a tune, 20psi
4L80, 3.73s
33's
20 mpg
6.5 Turbo Diesel with a tune, 20psi
4L80, 3.73s
33's
20 mpg
This is a great thread! 
Who the fock builds a k whatever and is worried about fuel mileage!
Who the fock builds a k whatever and is worried about fuel mileage!
This is a great thread!
Who the fock builds a k whatever and is worried about fuel mileage!
I worry all the time maxfocker02
My k20, 350/sm465/tons w/4:10s gets anywhere from 10-14 mpg.
My old 84 k5 on 33's would get about 16-17mpg. Mileage didn't change really going from a 305 and not using OD with 3.08 gears to a 350 and 3:73s using OD
I don't overly care about mpg on this stuff, I prefer to roll with smiles per gallon
hillbilly deluxe
Professional Pile-It
What tune? Mine is not getting 20 at all. I am running stock tires and 3.42s.
crashandburn
1/2 ton status
Sorry, the tune was in the truck when I bought it. No idea. A buddy of mine builds tunes, and out of curiosity he plugged his laptop in, but since it is so early in the ODB2 world, it would not let him see anything.
hillbilly deluxe
Professional Pile-It
Oh, bummer.
I have the Heath ECM and turbomaster. I think my MPG went down a bit after the tune, but it's so much more fun to drive!
I have the Heath ECM and turbomaster. I think my MPG went down a bit after the tune, but it's so much more fun to drive!
black dawg
1/2 ton status
v2500 tbi 454 465/gv 3.73 and 265/75/16
drove 300 miles this weekend, with 100 on gravel, and about 5 of that aired down crawling over snow.
13.2
drove 300 miles this weekend, with 100 on gravel, and about 5 of that aired down crawling over snow.
13.2
pma4x4
AKA Yankeeroad
Currently 10 loaded for 10 days if camping. I hope to be back up to 15 by this time next year after the TPI vortec swap.
350 TBI
700r
4.56 LSDs
33x10.50TBI
Bored TBI an 11lb fuel psi
350 TBI
700r
4.56 LSDs
33x10.50TBI
Bored TBI an 11lb fuel psi
Jessie James
1/2 ton status
1991 K5, 235k miles
5.7l engine, all stock except for an unknown brand of headers. Non-heated O2 sensor, which I need to change one of these years.
I just found out the air pump has been removed.
New injectors and most engine emissions equipment like EGR and coolant sensors, new cap, rotor, plugs, new cat, new single exhaust.
235x75x15 (stock size?) tires, but they make the odometer read slower than I am actually going. When it reads 68 mph I am really going 65 mph, so there is a slight difference.
I get around 20 mpg in town, but I am very, very light on the pedal.
5.7l engine, all stock except for an unknown brand of headers. Non-heated O2 sensor, which I need to change one of these years.
I just found out the air pump has been removed.
New injectors and most engine emissions equipment like EGR and coolant sensors, new cap, rotor, plugs, new cat, new single exhaust.
235x75x15 (stock size?) tires, but they make the odometer read slower than I am actually going. When it reads 68 mph I am really going 65 mph, so there is a slight difference.
I get around 20 mpg in town, but I am very, very light on the pedal.
Last edited:
That's gotta be a record for a stock motor w/ 235k on it!
If you're going slower than your indicated speed, you should be also traveling less distance than indicated. Did you correct the mileage number accordingly?
If you happened to forget the correction factor, you'd still be a little above 19mpg. Assuming the (unspecified) engine is a 350, that's exceptional mileage for in town. Well done!
What engine/tranny combination are you running?
Jessie James
1/2 ton status
No correction, as I am too lazy to perform math.
Yes, it is a 350, and I don't know what tranny but assume it's whatever came stock as well. I am super light on the pedal, though, which I am sure makes a huge difference. Everyone leaves me far behind when the light goes green, but I don't care. It is my "day off" truck, so I am in no hurry.
Everything is stock, top to bottom.
