Fuel Consumption

RivGuy · July 13, 2019

Now that I'm a new owner of a 5.3L engine I was wondering if others seem to find this engine consumes gas while it's parked in the driveway.???

I'm kidding obviously, but I'm just not used to this much fuel consumption. Even after having owned a Supercharged Riviera that I did a lot of mod's and mapping to. That car didn't burn nearly the amount of fuel this truck does and I had some serious mods done to the Riv.

Anyway, I know they are 2 different vehicles and 2 different engines and I don't know what the previous owner may have done to the fuel and timing mapping after having installed an aftermarket exhaust system. (FlowMaster) The exhaust sounds good but it also exits just before the passenger side rear wheels, for what that's worth.

I got heavily involved in the Mod's to my GM 3800 V6 Supercharged engine in the Riviera. From Stainless headers, high flow cat, cam, injectors, longer ratio rocker arms and stronger Valve springs to intake mods and finally the appropriate tuning from a guy that was on the forum and lived near me that ran his engine on the dyno during different modifications and saved all his tunes on his laptop. He was able to download a tune to my car that he had used in the past with the exact same mod's that I had and went with me to the dyno to ensure it was tuned perfectly after the mods were done. I didn't put the smaller SC pulley on until we were there, at the shop, and after he downloaded the complete tuning software to my PCM, then ran it on the Dyno to make some tweeks and confirm all was good and we were not experiencing any knock.

The overall plan was to let more air in and open the exhaust to let more out prior to putting a smaller pulley on the SC to spin it faster and get more HP and Tq safely. Which I accomplished.

I didn't try to blow the engine up. I did successfully make the engine more efficient while getting more HP and Tq at the same time.

Anyway, I'm not sure what, if anything other than the exhaust has been done to this truck but it sure feels like it has a lot of balls for a heavy 4 wheel drive truck. It accelerates as good if not better than the Riv and probably weighs 1 1/2 times the car but would beat it on any on ramp.

Without the proper software to hook up to the OBD2 port how would I know. What software is available for this powertrain so I can start to look at what the engine and trans is doing.

Does anybody have any suggestions on what the best tuning software would be.?

I'd like to hook the laptop up to the vehicle and determine where things are at and where I may be able to make some efficiency and power improvements.!!!!

Any help would be greatly appreciated. Just trying to learn more about this 5.3 engine and what can be done to make it more efficient.

Thanks a lot for any and all input,

Rick

Colossus · July 13, 2019

Best tune out there by far I believe is Black Bear. They are a site sponsor and lots of folks from on here have used them over the years. They are who I would use. Go have a chat with them. Justin and Jenna are awesome.

RivGuy · July 13, 2019

Thank you very much Ryan,

I appreciate your input. As I have said I'm clueless when it comes to this vehicle and engine but am eager to learn.

Rick

swathdiver · July 13, 2019

11 hours ago, RivGuy said:

Now that I'm a new owner of a 5.3L engine I was wondering if others seem to find this engine consumes gas while it's parked in the driveway.???

I'm kidding obviously, but I'm just not used to this much fuel consumption. Even after having owned a Supercharged Riviera that I did a lot of mod's and mapping to. That car didn't burn nearly the amount of fuel this truck does and I had some serious mods done to the Riv.

Rick, those Buick 231s and 3800s are some of the most efficient engines ever designed, hard to beat, even today!

We almost always remote start the truck and that consumes on average 1.6 gallons per tank of fuel. The motor is pretty linear with regards to fuel burn, mine has burned as little as 1.3 gph and as much as 4.1. With extensive idling it still comes out to between 1.3 and 1.7 no matter if burning high octane gasoline or any level of FlexFuel.

I went on Fuelly last year and did an average of averages of all of the Tahoes, Suburbans, Yukons, Yukon XLs with the Gen IV 5.3s found in the 2007-2014 GMT900 SUVs and found out that despite improvements, they all average 14.3 MPG.

BlackBearPerf · July 17, 2019

On 7/12/2019 at 5:38 PM, RivGuy said:

Now that I'm a new owner of a 5.3L engine I was wondering if others seem to find this engine consumes gas while it's parked in the driveway.???

I'm kidding obviously, but I'm just not used to this much fuel consumption. Even after having owned a Supercharged Riviera that I did a lot of mod's and mapping to. That car didn't burn nearly the amount of fuel this truck does and I had some serious mods done to the Riv.

Anyway, I know they are 2 different vehicles and 2 different engines and I don't know what the previous owner may have done to the fuel and timing mapping after having installed an aftermarket exhaust system. (FlowMaster) The exhaust sounds good but it also exits just before the passenger side rear wheels, for what that's worth.

I got heavily involved in the Mod's to my GM 3800 V6 Supercharged engine in the Riviera. From Stainless headers, high flow cat, cam, injectors, longer ratio rocker arms and stronger Valve springs to intake mods and finally the appropriate tuning from a guy that was on the forum and lived near me that ran his engine on the dyno during different modifications and saved all his tunes on his laptop. He was able to download a tune to my car that he had used in the past with the exact same mod's that I had and went with me to the dyno to ensure it was tuned perfectly after the mods were done. I didn't put the smaller SC pulley on until we were there, at the shop, and after he downloaded the complete tuning software to my PCM, then ran it on the Dyno to make some tweeks and confirm all was good and we were not experiencing any knock.

The overall plan was to let more air in and open the exhaust to let more out prior to putting a smaller pulley on the SC to spin it faster and get more HP and Tq safely. Which I accomplished.

I didn't try to blow the engine up. I did successfully make the engine more efficient while getting more HP and Tq at the same time.

Anyway, I'm not sure what, if anything other than the exhaust has been done to this truck but it sure feels like it has a lot of balls for a heavy 4 wheel drive truck. It accelerates as good if not better than the Riv and probably weighs 1 1/2 times the car but would beat it on any on ramp.

Without the proper software to hook up to the OBD2 port how would I know. What software is available for this powertrain so I can start to look at what the engine and trans is doing.

Does anybody have any suggestions on what the best tuning software would be.?

I'd like to hook the laptop up to the vehicle and determine where things are at and where I may be able to make some efficiency and power improvements.!!!!

Any help would be greatly appreciated. Just trying to learn more about this 5.3 engine and what can be done to make it more efficient.

Thanks a lot for any and all input,

Rick

We would be happy to help with tuning. We can tune your vehicle with our AutoCal, the hardware is yours to keep, it allows us to see your vehicle data, and provide your custom tune files via email. We can also tune it with our Scan Cable, you would submit a deposit for the cable, and data log, and email that in, then we will physically tune the computer and mail that to you. Give us a call 877-809-4070 or message us here with any questions.