New Sierra HD with 6.6 gasser ordered, wondering about cSt

Slow for a car, but in the truck world a Titan punches well above its weight.
My heavier 2010 Armada is still consistently hitting 0-60 in sub-to-mid 7 seconds, according to multiple Android speedometer apps I tried.
And both my EVs are faster than that and they’re slow for EVs. Not sure how a Titan is relevant to what oil the OP needs.
 
I gotta say - all these serious replies are definitely more entertaining than the video. 😉 Y'all fellas seriously got triggered! 😅
Go Nissan! 🙃
Nope, not at all just a stupid comparison and has nothing to do with actual truck things. No one said the truck or Nissan were bad. Might as well compare that truck to my Trans Am or Caprice.
 
I gotta say - all these serious replies are definitely more entertaining than the video. 😉 Y'all fellas seriously got triggered! 😅
Go Nissan! 🙃
A guy posts that he's going to buy a new truck and asks about oil and you post a video of an old Titan "spanking" one and the implication is very clear the old Nissan truck is better than the new truck. No other reason to post it. Maybe the Titan is boosted. Maybe the Silverado had 3000 lbs of sand in the bed. Maybe the Silverado driver chicken footed. Meaningless video. But it's HIGHLY entertaining if you're a Nissan fan!?. Like I said I've owned both trucks and the Titan is a great truck, better than most give credit, but it's not close to the 6.6 gas 2500 Silverado for serious truck use. You're impressed with truck drag races and 0-60 times. Nothing wrong with that but not many guys are.
 
If it was me, ESP or M1 Supercar with dexosR. But I’d run M1EP or Castrol Edge FST with D1G3 certs and keep an eye out on oil temps. Because warranty. The 6.6 doesn’t have AFM on it?
 
Obviously trucks are not for racing, but...
I find it VERY entertaining that an ancient 20+ year old Nissan Titan with half the transmission gears and full liter less displacement spanks the GM 6.6. And the Titan ain't no slouch when it comes to towing either.

Heavy duty truck engines are purposely derated vs half tons or other applications where the goal is fuel economy or max performance. An HD truck is tuned for duty cycle, climbing a grade for 15 mins straight at 4500+ RPMs with it's full rated trailer GVWR behind it, day after day. If you want proof of that, look for example at my truck where my engine (5.7 hemi) is rated at 395 hp but in the 2500 it's down to somewhere around 380 IIRC. Same engine, different tune. And the 5.7 is still basically just a car engine doing truck things, a real HD engine like the 6.6 or the Ford 7.3 are tuned down even more.

In other words, this is as useful as comparing a farmers tractor to a highway semi. Just don't.
 
Oye. But then again, there’s company trucks that see only bulk D1G3 oil and there’s no stories of those blowing up… yet.

I feel these GM V8s aren’t picky about oil. AFM is another thing.
The LT engines don't suffer carbon deposit build up problems like other vehicles. They have been around since 2014. A failure of an injector from time to time yes. The 6.6 was introduced in 2020 there are guys out there with over 300,000 miles on them already.
 
L8T 401 HP and 464 FT/lbs of torque.

May I introduce the L8P, which I would love to drop in the Caprice.

Just a less detuned L8T. Would drop right in OPs and my truck easily.

523HP 543 FT/lbs of torque. $8,948.00. I don't think that is too shabby.

L8P

So as you can see the L8T is detuned for duty cycle which is probably the most important thing in an HD truck.

Sorry OP, but you are going to get this extra data and like it. :) :D
 
Last edited:
Heavy duty truck engines are purposely derated vs half tons or other applications where the goal is fuel economy or max performance. An HD truck is tuned for duty cycle, climbing a grade for 15 mins straight at 4500+ RPMs with it's full rated trailer GVWR behind it, day after day. If you want proof of that, look for example at my truck where my engine (5.7 hemi) is rated at 395 hp but in the 2500 it's down to somewhere around 380 IIRC. Same engine, different tune. And the 5.7 is still basically just a car engine doing truck things, a real HD engine like the 6.6 or the Ford 7.3 are tuned down even more.

In other words, this is as useful as comparing a farmers tractor to a highway semi. Just don't.
Yea, the Nissan VK56DE/DD(Titan/Armada/Infiniti QX56) and Toyota 3UR-FE/FBE(Tundra/Sequoia and Lexus LX570/LC200) are rev-happy and built to be smooth, seeing their base was a luxury car V8. There’s a reason why Isuzu didn’t use a Nissan or Toyota V8 as the gas engine for their NPR trucks - they chose the GM 6.2/6.6 instead.

The “heavy” truck gassers - Ford Godzilla, GM’s 6.2/6.6 are meant to work and emphasize low-end torque. Cummins is also using Ford and GM’s playbook with the new gasoline variant of the B6.7.
 
6.2 is a half ton GM engine there are UPS trucks and NPRs with the 6.0

6.0 NPR

6.2 is all aluminum and has AFM. Not used in HD applications.

Ford has a nice HD 6.2
 
Last edited:
I have a 2024 6.6 gasser I tow 3 different trailers with it. It is just a big LT based engine (L8T) without AFM/DOD or whatever they are calling it now. I just run plain ole Dexos 1 Mobil 1 5W-30. Why wouldn't you under warranty? I see no reason why you would run anything else that isn't Dexos.

I will say this, I have oil catch cans on my Trans Am (LS1) Caprice (L77 think LS2ish) and I have one on the L8T/6.6. The L8T is the only catch can that grabs any oil.

When you get the truck check ALL the fluids my front and rear diffs were low and check all the grease fittings. Some of mine were dry.

Having said all of that I am at 7000 miles on the truck. Did my first oil change at 2000 miles and the second at 6000. I plan on 4000-mile oil changes. 90 percent of that is towing. The Mobil 1 does just fine in there.

What color and trim level did you get?

View attachment 274692
LS1Mike, Ill get it Friday its an SLE, with most of the options available Black Onyx ... the stock was very low so the choice of color was minimal ... I had an F150 white before, i didnt want a white truck again... Ill have to work a lot harder to keep it clean for sure .
I've made my bed and Ill run Mobil 1 Advance . 5w30 like you I think. the oil was on sale this morning , and is readily avail;able almost anywhere in canada and in the USA. I looked at the spec and question 3 different AI on the subject :-) most of the time this oil was choosen by one of these robot for the quality performance vs price .... so thats what the 6.6 will get .... now I cant wait for friday :-)
 
Heavy duty truck engines are purposely derated vs half tons or other applications where the goal is fuel economy or max performance. An HD truck is tuned for duty cycle, climbing a grade for 15 mins straight at 4500+ RPMs with it's full rated trailer GVWR behind it, day after day. If you want proof of that, look for example at my truck where my engine (5.7 hemi) is rated at 395 hp but in the 2500 it's down to somewhere around 380 IIRC. Same engine, different tune. And the 5.7 is still basically just a car engine doing truck things, a real HD engine like the 6.6 or the Ford 7.3 are tuned down even more.

In other words, this is as useful as comparing a farmers tractor to a highway semi. Just don't.
Bingo.
You can get a ram diesel rated over 400hp.

Or you can get an X15 rated at 400hp. Now, which one is going to last longer if asked to deliver an actual 400hp worth of work?
 
IM about to buy a 2025 sierra HD with the 6.6.
This truck will tow close to 8000lbs for about 8000km a years and maybe 3000 km as a grocery getter.

GM spec 5w30 Dexos 1 gen3 and I would like to run a 5w40 but I really do not want to screw up my warranty so I will remain within the GM requirement

X Grok AI told me that Valvoline advance is close to the max for a 30 on the viscosity chart something like 11.9 cst do you have any recommendation for me , I need something readily available in Canada .

Does it really matter to look for cSt and or is it a number I should focus on to protect my new engine if I tow in the heat of texas or in the Pen. and or Virginia mountain ?

Thanks guys
Don't overthink this. A couple cSt within 30 grade isn't going to make a lick of difference. What will matter is HTHS and additive pack.

Find the full syn D1G3 you prefer (thicker, higher HTHS, whatever) and keep it fresh and you'll be just fine. Don't overthink this.

I'd be plenty happy to run any of several D1G3 oils. I'm partial to valvoline and M1, but there's no reason to think any D1g3 won't work superbly if you just keep it fresh.
 
LS1Mike, Ill get it Friday its an SLE, with most of the options available Black Onyx ... the stock was very low so the choice of color was minimal ... I had an F150 white before, i didnt want a white truck again... Ill have to work a lot harder to keep it clean for sure .
I've made my bed and Ill run Mobil 1 Advance . 5w30 like you I think. the oil was on sale this morning , and is readily avail;able almost anywhere in canada and in the USA. I looked at the spec and question 3 different AI on the subject :-) most of the time this oil was choosen by one of these robot for the quality performance vs price .... so thats what the 6.6 will get .... now I cant wait for friday :-)
You will love it. I came out of a 2017 6.0 1 ton gasser and I wasn't sure at first but I love and it tows my 9000 lbs trailer with ease! Black always looks so good. I don't daily drive mine, but it is easy to live with and I get 8 to 9 mpg towing and 15 to 17 mpg highway. Average with everything over the time I have owned it is 11 to 12 mpg. Enjoy it!
 
Grease your front end. Everything has a zirk fitting. Mine was dry. My rear axle took a whole quart to fill it up. My front diff was good. I had a 2014 1500 silverado 5.3. At 168k camshaft deamination. Dealer mechanic let .e see it apart. It used some oil but not a lot. I did tuner the afm at 100k at end of warranty. My intake valves were not caked up. No catch can.
 
Back
Top Bottom