CoolHandWayne

Amsoil claims dexos 2 compatibility. Is it really not "certified" because GM hasn't chosen to test it? Either way, if your dealership is going to deny a warranty claim because of using amsoil, I doubt there is much chance of getting anything major covered under warranty there.

Has anyone changed their atf in the 8 speed? I want to swap to amsoil atf before long and I was going to get the dealership to do it but it looks fairly easy from what I can find. I'm around 20k now and I am thinking about changing it around 25-30k, not because it needs it of course but I'd like the better fluid in there and I figure after 25-30 it's good and broken in and should be producing less sediment at that point. That's my thought anyway.

So what air filter is good for the stock box? I pretty much see the oem replacement and k&n but it sounds like the k&n isn't actually that great for this truck. Any good dry options that flow better than a stock replacement?

With today's quality standards I'd never expect perfection! I hope this doesn't end up being a prominent issue though. I expect that problems like that arise from poor lubrication.

Sweet! I had looked a while back but not recently. Thanks for posting.

I also would like to see a tune. My interest is more in fuel efficiency though. I think major improvements could be had with only minor reductions in driveability.

Very curious to hear your results with the Amsoil atf in terms of mpg. I have been planning to do that but the cost is deterring me. If I can't get at least 1 mpg out of it I don't think it's worth changing it out too early.

Thanks. I will contact him.

Please elaborate. Is there a different lab that would do a better test? If the fuel content is over 1% why would Blackstone say it is less than 0.5%? This is a concern I have so more information would be appreciated.

Got my first oil report back today. 15k on the truck and 4800 on this oil. Oil was Motul 8100. Looks good. I was worried about the fuel content after hearing that might be a problem with these. But no concerns here. I used amsoil after draining the Motul to do a comparison. Probably will go 6k or so on the amsoil.

I drive pretty carefully to get good efficiency. Most of my driving is in a 60mph zone. I'd like to drive 65 but going 55 makes a huge improvement. I use down hill stretches to pick up a few mph and allow the truck to slow down some when going up hill. Tbh, I watch the instant fuel consumption reading more than the speedometer. If the instant reads low I slow down. If it's high I speed up. I recently got my 400 mile average up to 27.8. it's down to 26.6 or so now after some city stop and go but I was pretty impressed.

I see. Thanks for clarifying. I'll post test results after I drain it and compare to amsoil.

So, CustomBoss, are you saying you don't think the 8100 meets criteria for use in this engine?

Sorry, I think it is 8100, not 8300. And when I mentioned seafoam treatment I meant introducing it through the intake air stream. Which yes, would likely be rather difficult in a turbo application. But my thought is that that would be the only option to give the valves some cleaning action. I've done intake seafoam treatments before with impressive results but only in older vehicles.

The oiled air filter being a potential concern with a DI engine had crossed my mind. I figured it's relatively so little oil in it that it couldn't be but so bad one way or another. May end up back with the OE filter though. I am currently running Motul 8300 which claims to be specifically formulated for DI and turbo engines. I'll get that tested after 5k or so and see what the saturation is like. I also wonder if a periodic seafoam treatment is a good idea to combat any potential buildup on intake valves? Thanks for all your thoughts and explanation on the matter.

There seem to be a handful in this thread with some pretty in-depth knowledge of this engine. Does anyone know what features GM employed in this engine to combat build up on the intake valves? As far as I can tell there is no port injection system and many engines running on direct injection alone have had problems with build up on intake valves due to no fuel flowing past them and cleaning them. I have heard of other solutions though. Anyone know? What are the chances these engines end up needing periodic valve jobs to clean the intake valves?

Custom. Not lifted. No bed cover. Quad cab 4x4. Original wheels and tires. Windows up or cracked.

No no. Average is definitely higher than that though I can't say exactly. Somewhere closer to 58. I am not on interstates much. Rural 45, 55 and 60 mph zones. Though to keep the mpg average high I do take opportunities to make certain drives around 50 when I reasonably can. Though from the sounds of it maybe I should be doing even better. I am using good engine oil, currently motul 8300 though usually amsoil, I put redline in the rear diff, and a k&n filter all just to keep efficiency up. Last things to do are amsoil atf and maybe some semblance of an under tray to help out aero just a tad. Nothing overboard.

I've been watching this thread since I started shopping for a truck. Thanks to all those that have contributed such informative posts. I bought a quad cab 2.7 4x4 in August of 2021. I was sweating it with this new engine. It drives great but I was nervous. I've put some effort in to improving fuel efficiency and lately I've dropped the cruising speed a few mph to mitigate the cost of gas. I'm satisfied with the results. I am actually doing better than I expected but it would definitely be nice to be able to do this at 5-10 mph more!