MPG

[RichLo]

yea, same with mine, I dont drive it enough to worry about it. It's also well maintained but I have a Chevy Cruze as my daily since I drive around 80 miles for my daily commute.

 

[PlayingWithTBI]

Check for vacuum leaks by spraying carb cleaner around the throttle body (the shaft has a tendency to wear out the body) and hose connections. Timing chain will affect it too.

Chip tuning will help a bunch. There is a "HiWay Lean Cruise" already in the Bin file your truck uses, it was disabled by GM because they couldn't pass emissions. You can also disable the EGR in there...

I pumped up my 88 RCSB 5.7 with aluminum heads (2.02/1.60 valves), headers, high flow cat, fairly mild Lunati Voodoo cam, Edelbrock 3704 intake, 46mm throttle body with 18lb spring, a "performance" chip tune, with 4.10 gears and am getting 14mpg average (0-60 in 7.6 secs) without HiWay lean or EGR delete because I live in Maricopa County AZ where they test every 2 years. I may do it anyway and keep 2 chips - one for every day and one for emissions.

After data logging and more tuning I'm looking to get closer to 20MPG

 

[c1500deathtrap]

Thanks! Much better.




Is the timing chain replacement the same for all the SBCs? I see some videos for the 5.7 but not 5.0.

If someone could point out a video or write up for the process I would appreciate it!

Thanks.

yes. its the same.

 

[Deathpunch0311]

I have a 98 5.7 ecsb lifted 6” on 33x12.50r18 all terrains. 3.73 true duals, Flowmaster 40s, new motor and trans and I get 12 city and 16-17highway. Depending on how I drive

If I wanted good MPG I would get a car.

I love my truck.

Got the same mpg as my wife’s old 2013 ram 1500 2wd hemi.

 

[Deathpunch0311]

Chip tuning will help a bunch. There is a "HiWay Lean Cruise" already in the Bin file your truck uses, it was disabled by GM because they couldn't pass emissions.

Is the hiway lean on the later vortecs or just the TBIs

 

[PlayingWithTBI]

The 1227747 ECM used the $42 bin and the 16197427 used the $0D bin both had them from factory but depending on what BCC your truck uses, may or may not. A lot of guys have "hacked" them for HiWay Lean. Download TunerPro RT (free) and look at themat this link.

http://www.gearhead-efi.com/BCCFind/

 

[L31MaxExpress]

Is the hiway lean on the later vortecs or just the TBIs

Black box does not but the 0411 does.

 

[tanman_2006]

Is the timing chain replacement the same for all the SBCs? I see some videos for the 5.7 but not 5.0.

It should be the same for a 4.3, 5.0, and 5.7. Nothing special: pull the fan, fan clutch, water pump, crank pulley, and then pull the timing cover.

 

[L31MaxExpress]

It should be the same for a 4.3, 5.0, and 5.7. Nothing special: pull the fan, fan clutch, water pump, crank pulley, and then pull the timing cover.

My one recomendation is use a single roller chain. They are a little more money but well worth it even on a stock engine. GM used them from the factory on the HD 350s and marine engines.

 

[c1500deathtrap]

My one recomendation is use a single roller chain. They are a little more money but well worth it even on a stock engine. GM used them from the factory on the HD 350s and marine engines.

Part number is 12371043