Guy's with 5.3 in k5 post your fuel mileage up

[Larry]

Wholy crap.....didn't realize how old this thread was....call me a sucker

 

[ZooMad75]

Wholy crap.....didn't realize how old this thread was....call me a sucker

Ok. Sucker!

 

[handloader90]

Smaller engines do not always equal better fuel ecomomy. The Polar Bear 1989 V2500 Suburban w/ 8.1L pulled a total trip average of 13.9 last month on our annual Desert Trip. The best I ever got out of the old TBI 5.7L was 11. The trip was around 1,850 miles with a mix of highway, mountain passes and about 600 miles of off-roading. Not too bad of mileage for a big tank with damn near 500 cubes under the hood. Our old 2004 Tahoe Z71 w/LM7 5.3L used to get around 13 city and 17 highway and had a lot less power but I doubt that mileage would be expected in a swap into a square body. Don't overlook big engines. A lot of it has to do with driver habits and the trans. Big engines don't have to work as hard to propel heavy metal down the road

Been looking roumd more, jumped on LS1tech and have been reading up.

Leaning more towards the 5.3 LM7 now instead of the 4.8.

I just wanna get rid of the carb and distributor, flat tappet cam etc.

Gas mileage is definitely a plus but I wanna be able to get crazy with the skinny pedal too.

 

[Babaganoosh]

I get about 12mpg in my c10 turned k20 with about a 4 inch lift, 35's and a LQ4 6.0

It used to get about 7mpg with the 350 31's and 3.08 gears and 2wd suspension.

 

[wetoolowdingbangow]

The only reason I'd be doing a 4.8 is if it had twins. The 5.3 could use a turbo as well. Lol.

A lot of the mileage is made up in the drivetrain.

 

[ZooMad75]

I haven't had too many road miles with my 5.3 in the K5 but what I have is already better than the old 350/465 combo. I'm running the same height tires that was on either but it's better on the 91 with the 5.3. Couple of factors, the gearing for the tires is better at 4.10's on the 91. The EFI is a major factor to better mpg's too for sure, but having the OD in the 700 is the key.

Just an example in the old 75 with the qjet 350, a run to Larry's house and back would use a 1/4 tank of fuel. I've driven twice to Larry's place and the needle barely moved a needle with from where it was at. I know it won't be 20mpg's, but double the 350's crappy mileage would be a plus.