00pooterSS

iTrader: (40)

Picked up a 2014 5.3 last week and my real question is has anyone noticed any change after headers in MPG while driving the same as they did before. I want them for the power gain but also curious if they had any affect/effect on MPG.

I know it sounds counter intuitive to try headers but anything that increases efficiency should be able to help MPG as well since they go hand in hand. Then i'd tune it afterward. My 2004 was on a 93 tune with aggressive ignition timing and i'm getting the same MPG now I was with it, and I was expecting better.

This truck came with a K&N, I changed the trans fluid, diff fluid, did an induction cleaning (clean valves), set the alignment perfect and aired the tires up to 40 PSI.

Also anyone seen a before and after dyno with factory catback with headers vs aftermarket catback? Curious how good the stock stuff is, it's a decent size pipe and mandrel bent, figuring it does pretty well.

colekill

Tell me more about this induction cleaning you did

00pooterSS

iTrader: (40)

Fast forward to 4:24 to see the tool I use. It turns whatever cleaner you pour into it into a mist. It's actually a touchless throttle body cleaner tool but I use it for induction cleaning. I used Wynns combustion chamber cleaner and ran the engine with it misting into the throttle body for 10-15 minutes. Idles considerably smoother now. The truck has 113k and idled rough when I got it. All standard stuff checked good (spark plugs) so figured it was dirty DI valves.

CDC makes a spray in induction cleaner that supposedly works well but I like the tool I use because it turns fluid into a mist and distributes better than a spray would.

Vortec350ss

iTrader: (20)

A tune is really where gains in efficiency will come from rather than improving its ability to flow air.

Atomic

iTrader: (42)

Dont expect any improvements or drastic changes. Biggest thing you can do for your mileage is drive slower and put on lighter weight wheels/tires.

00pooterSS

iTrader: (40)

A tune is on the list using higher octane to run higher timing. Looking for results of someone trying this and other things and what their experience was. I got approx 2mpg on the 04 with the 93 high timing tune. Haven't found any results of someone trying it with an ecotec 5.3

Improvements can be made, I don't expect drastic changes. I looked into lighter wheels already, a couple of years ago anyway for the 04 and HRE has some that weigh in the 20 ish lb range but they're something like 2200 a piece.. The truck has goodyears on it now, when I replace the tires I'll look for some that hopefully may be a little lighter and possibly also LRR.

The stock truck wheels I believe are in the mid 40 pound range. When I looked before at wheels I couldn't find any under 40 pounds or upper 30's that were under 1k a wheel so the lightweight wheel option isn't an option for my bank account. Unless you can steer me toward one. And honestly at this time I'd be looking to spend closer to 1k for a set. Even at 2k a set I'd be out.

I'm aware no big changes are gonna happen, I just like to research and see what the real world experience is. I've even considered looking into things like crank scrapers to reduce drag. I'm probably going way too far but I'd love to make more power and get better MPG. It can be done. I just don't always follow the crowd on how I do things.

Main reason I posted here was I googled this mpg and headers and tune thing a lot and keep seeing a lot of half *** info, and people saying they didn't gain anything with a tune, which sounds like horse **** to me, i've seen the gains from tunes with LS stuff. There's other people like me that like to tweak and test tweak and test and I'm hoping to find someone that's done that with the ecotec. Just like you did with your bump stop drilling. I still remember that thread and I was happy to see someone else that likes critical thinking and testing.

Noah Burns

iTrader: (5)

this! Tuning is where the biggest gains came from on my 2014. LTs and a tune my mileage went up a ton. the converter killed all that tho...

FFDP

iTrader: (2)

You don't have to run higher octane to have higher cruise timing, well not 91 or 93 anyway. Running 89+ is a good idea in my eyes for any LS truck as I don't like trying to work with 87 octane myself. Optimizing the VVT and overall timing curve should help and of course driving slower.

Of the countless trips up north and out to Montana, my uncles truck continues to get him 21-23 on the freeway almost every trip. Of course mixed driving is still around 18-19ish.

00pooterSS

iTrader: (40)

I knew tuning would help that's basic knowledge there. And the keeping your foot out of it.


That's what I was looking for. Did you have stock catback as well? I have zero plans to do a stall, this truck launches hard enough stock to satisfy what I want and I'll be pulling a boat, my 04 wouldn't spin a tire to save it's life, this one will spin both no problem and will get better with tune and LT's. I've ran stalls before and know all about the MPG woes with a big stall.

The higher the octane the higher the timing the higher the mileage. I don't mind paying for 93 to reap the largest benefits. More powaaaa too.

FFDP

iTrader: (2)

89 octane and 91/93 octane would be able to run the same cruise timing, the octane does not matter as much at low loads.

Even when going for all out power, you likely will not feel the maybe 10-15hp difference in the butt dyno. DI engines can get away with less octane is some cases because the fuel is shot straight into the combustion chamber. It's not a lot of money per fill, maybe 6-8 dollars but just saying that octane isn't everything when the engine is stock.