2.7 Turbo 4 Fan Club

[Black02Silverado]

1 hour ago, customboss said:

On MPG optimization with this engine (L3B) design, it is tuned to perform like a spark ignited diesel with associated low RPM TQ (1500-3000 RPM) so if you are throttling it like a V6 or V8 it may feel good but you might be wasting the good TQ with low fuel burn capability. 

 

310 HP is plenty to keep the unit in motion but 348 or 420 ft lbs of TQ available at 1500 rpm means you need almost no throttle and let that dual volute turbo do its work. 

 

I am a former HD diesel OEM  R&D engineer and we focused on the optimization of VGT turbos to make lots of tq and hp out of lower displacements with boost and DI fuels injection. 

 

I filled up for second time yesterday using 85 octane CENEX gasolines. 20.74 mpg average.

 

I let that turbo and Tq to pull me ahead with 1500 RPM range to accelerate. I don't tow but I am in a 2022 Trail Boss Custom 4X4 that operates at very high altitudes, cold ( single digits in AM or nights, rough mountain gravel roads, slick icy, snowy, high wind 2 lane highways), I am in and out of Autotrac, 2WD, 4WD so far in 729 miles.  I changed out the oil for optimum wear-in reasons @ 592 miles to effect better more optimized break in. 

The QS full syn dexos1 gen 2 installed is probably lower quality than the OEM fill that I believe was Dexos1 Gen 3. However cleanliness is key for why wear in technique. 

 

On the flat with winds whipping in and out of 10-20 mph mostly cross winds I see :

 

25 mpg @ 45-50 mph

22 mpg @ 65 mph

21 mpg @70 mph 

 

Think about the turbo being your throttle not fuel flow. Focus on torque unless you just want to waste fuel and go fast or tow fast. 

 

My 2 cents. Not gospel. 

 

 

So I take it you like the Trail Boss better than the Ridgeline? 

 

 

 

 

 

 

 

 

 

[customboss]

Yes I do!

[customboss]

Heads up for L3B friends : https://gm-techlink.com/?p=15506

[f8l vnm]

That's interesting. we haven't received anything from GM yet .  Should we even? We have Four 2.7s in our fleet all of them 2020;s

[customboss]

Sadly nor will you.  Unless you have a subscription to Tech Links. TSB's aren't sent out to customers, only dealers and thats if they pay attention or care. If you don't complain of an oil leak you won't hear a thing.  Only NHTSA recalls are alerted to.  Squeaky wheel gets grease. Its not broad based enough for a recall. 

[f8l vnm]

2 hours ago, customboss said:

Sadly nor will you.  Unless you have a subscription to Tech Links. TSB's aren't sent out to customers, only dealers and thats if they pay attention or care. If you don't complain of an oil leak you won't hear a thing.  Only NHTSA recalls are alerted to.  Squeaky wheel gets grease. Its not broad based enough for a recall. 

 

Thank you for the heads up! 

[customboss]

YW Sir! 

[David Bodine]

All the manuals and window sticker show my 2022 2.7T Silverado Custom to only have 348 Torque, not 420.  ??

[f8l vnm]

11 minutes ago, David Bodine said:

All the manuals and window sticker show my 2022 2.7T Silverado Custom to only have 348 Torque, not 420.  ??

You sure your not looking at the Old/New model ? LTD i think they call it ?  We now know the refreshed ones wont be out till mid year maybe. 

[Mike Borowski]

20 minutes ago, David Bodine said:

All the manuals and window sticker show my 2022 2.7T Silverado Custom to only have 348 Torque, not 420.  ??

The new engines aren’t out yet I dont think. 

[David Bodine]

OOPs,  I took another look at the window sticker. It only show 3.7T engine nothing about the torque, however; I have noticed on some of the inventory of 2022 silverado show only 348 torque. I will get my engine number and do a little more research.

[David Bodine]

I am new at this so I'm not sure where to submit my answers or comments. Is this reply only to one person? I summited earlier that I took another look at the sticker and it did not show torque, only that it is 2.7T. I'm going to look further on this.

[customboss]

4 hours ago, David Bodine said:

I am new at this so I'm not sure where to submit my answers or comments. Is this reply only to one person? I summited earlier that I took another look at the sticker and it did not show torque, only that it is 2.7T. I'm going to look further on this.

David, when you post here we are all reading your posts as a group. You can have a private conversation directly with anyone that will accept it. 

 

My 2022 LTD Trail Boss Custom has the 2.7T and I was told by my dealer it was a 420 TQ model when he looked it up. My window sticker just says L3B 2.7L T no specs. 

 

A kind person on this group looked up what he could from GM and thinks its a 348 TQ because of the engineering RPO code J21 but the dealer disagreed, then hedged, so I am not fully sure nor can I trust but verify. 

 

In my estimation one should be able to plug in the engine code as if you needed to replace or rebuild it and get the exact build. The person that had the GM tech access showed me he did that and the older engine design came up.  Once again the dealers Service manager could not confirm. 

 

Regardless I love it and drove it today @65 round trip to Las Animas CO today and it achieved 31 mpg with a good tail wind, on way back to La Veta CO area up wind and climbing from 4000' to 10,000' + 16.1 mpg     So overall average = 23.6 same route round trip, same temps, wind and grade differences. It was super smooth and powerful for a full size pick up with 2" lift! 

 

 

 

 

 

 

 

 

[customboss]

First oil analysis :   Fuels dilution ( target 0.5% or less)   elevated otherwise normal for OEM lubricant at 592 miles. 

 

Oil was changed with QS Full Syn 5w30 Dexos1 gen 2 and PF 66 oil filter. 

 

Note there is no lead alloys in this design ( or any modern GM)  so I think that is RTV and bonding agents result.  Silver is ring inserts and turbo alloys along with RTV. 

 

Nitration is a direct reading of combustion efficiency and EGR function result showing great ring seal and NOx low.  We have about 1000 miles on it now and it is getting better MPG on each run.  I did do some very aggressive low RPM, ring seating  lugs on La Veta Pass hwy 160 in Colorado and that should improve even fuels dilution.  Note the dealer idled the vehicle for probably 2 hours or more before delivery and fuel residuals will NOT burn off anymore like days of old. 

 

AC Delco Dexos1 gen 3 ( contract made by XOM)   most likely this oil chemistry. Still evaluating that.  

 

 

[Jaolered]

On 12/9/2021 at 3:56 PM, SilveradoRST said:

Is it mainly fuel economy the 10 speed does better?  I know some say the 10 speed shifts smoother but seems like the 8 speed with the new fluid can shift fairly smooth as well.  

What new fluid are you referring to? I have a 2021 2.7 with 26,000 miles. It shifts rough every once in a while. I am hoping we get the new transmission update that's coming with the 2022 refresh as well (supposed to have quicker downshifts and smoother shifts in general)