New Member Seeking Advice

ccoon21 · July 13, 2021

First post here and I’m looking for some advice…..

I’ll be upgrading at the end of the year from a 2011 Sierra 1500 with the 5.3L to a 2021/2022 Sierra 1500. However, I’m needing some advice as I’ve been going back and forth between the 3.0L diesel and 6.2L gasser.

I’ve already ruled out the 5.3L in the new one as my current truck’s fuel economy went in the tank after adding 33in MT tires. This new truck will be used as a daily driver just like my current one.

1. My Monday-Friday work week consists of me driving approximately 190 miles (very few highway miles)

2. From November-January during duck season, I trailer my 18ft surface drive almost every weekend to the launch (46 miles round trip)

3. I also will pull a side by side on a small trailer to the deer lease at the beginning of the season and then it home at the end of the season. I’ll make 2-3 trips total during the season (1200 miles total with 400 towing-mainly interstate driving).

I initially thought that with the towing I’ll do and eventually adding heavier tires, I’d be better off with the 6.2. However, with the daily driving I do and fuel costs increasing (especially 93 octane), I’ve been somewhat put off the 6.2.

On the other hand, with diesel being slightly cheaper and the 3.0L getting better fuel economy, it seems that the need for more maintenance that comes with a diesel could make the fuel savings a wash. Adding the heavier tires that I need for being off-road also concerns me for fuel economy.

I apologize for the wall of text, but I’d greatly appreciate any advice y’all could give me to steer me in the right direction as to what would suit me best.

steelcity · July 13, 2021

5.3

OnTheReel · July 13, 2021

The current 5.3 paired with the 10 speed is a pretty strong combo. Nothing like the GMT900 you have now. I would at least give it a test drive.

The 6.2 is a thirsty bastard, no way around it. I’m lucky to get 18 highway and 12-13 around town. The power is awesome but if you value economy, forget it.

Amcguy1970 · July 13, 2021

36 minutes ago, OnTheReel said:

The current 5.3 paired with the 10 speed is a pretty strong combo. Nothing like the GMT900 you have now. I would at least give it a test drive.

The 6.2 is a thirsty bastard, no way around it. I’m lucky to get 18 highway and 12-13 around town. The power is awesome but if you value economy, forget it.

No way, in every 5.3 vs 6.2 thread all the 6.2 guys say it is equal to the 5.3 on mpg while way faster than the dog they call it 5.3. So someone that actually has one in an unbiased view says otherwise?

Honestly OP if MPG is a concern the diesel will be the best and it isn't much more expensive. I have never wanted for more power with my 5.3/6 speed combo but my 1 inch larger tires are also standard load, so I can't comment on 35's and e-rated tires though. The more gears that have been added the better it helps with larger tires. My 5.3/6 combo is good, I imaging the 5.3/8 is better and I have heard great things about the 5.3/10 combo, the steep gears really off set larger tires or the need to re-gear. Engine wise I would go with the diesel as the 6.2 even with more power is going to be worse turning larger tires and with a recommendation for premium too...

Tyler

AlaskaErik · July 13, 2021

On the highway my 6.2 gets over 20 mpg. Better than my 2016 5.3. For a lot of long distance driving I'd consider the 3.0. Driving short distances and never letting an engine warm up is much harder on a diesel than a gasser, but that doesn't appear to be an issue with you.

steelcity · July 13, 2021

30 minutes ago, AlaskaErik said:

On the highway my 6.2 gets over 20 mpg. Better than my 2016 5.3.

10 speed with the 6.2? What transmission with the 5.3?

Firehawk99 · July 13, 2021

I have had both. A 2020 5.3 10 speed trail boss and a 2021 6.2 10 speed trail boss. I traded the 5.3 in for the 6.2. The 5.3 had adequate power for sure, but the 6.2 is on a totally different level! Honestly after having the 6.2 I will not go back to a 5.3.

As far as fuel mileage goes they were very close. I took the 6.2 on a trip from NY to FL with only 6 miles on it. And averaged 18 mpg with 5 people and the whole bed loaded. I reset it on the way home at Erie PA. from there to Buffalo I got 21mpg. If you take it easy you will easily see over 20 on the highway. Around town I get 16-18mpg. The 5.3 got about 1mpg better. I have always run 93. Although I have buddies at work who also have the 6.2, they use 87 and swear they get better milage with it. I just feel it's worth the extra couple bucks to get all the power I paid for.

6.2 all the way! Trust me you won't regret it!

American Cobra · July 13, 2021

40 minutes ago, Firehawk99 said:

6.2 all the way! Trust me you won't regret it!

This^^^^

Also had both. The 6.2 with the 10 speed is near perfection. Others are just fine.

ratman6161 · July 13, 2021

FYI , while the 5.3L+10 speed combination theoretically exists, you aren't likely to actually find one. On the Sierra, it's no longer offered on any trim lower than the SLT where the online build tool says its more $$ than just getting the 6.2 with 10 speed, though 10 speed is standard on AT4 and Denali.

I've got a Sierra 1500 SLT with 6.2 and 10 speed. I've only had it a week. I'm still in the break in period so I'm not doing long streatches in cruise but I've got a best 25 miles 9f 21.5. Anecdotally it seems to be getting as good or better than my 3.6L Canyon did on the same roads. I haven't towed the travel trailer yet but looking at the gearnratios on the 8 speed vs 10 speed I'm expecting it will do be better than the 8.

For those getting poor milage, do you have the 3.23 rear end (standard) or the 3.42 (max towing package)?

ratman6161 · July 13, 2021

PS: IF towing big stuff is needed, you cant get the max tow package with the 3L diesel. Also, without the max tow package, the 6.2 gets a lower tow rating than the 5.3 because its heavier. My Sierra has a tow rating of only 8600...which is plenty for my 6800 GVWR trailer but something to be aware of.

OnTheReel · July 13, 2021

I have the 3.42s which doesn’t help economy. Love the performance but it’s a pig. Granted, I also drive “Chicago” highway speeds which is to say I still get run off the road at 85. Only way I ever see 20 MPG is at 65 on flat ground.

The 5.3 10 speed is hard to find right now, but presumably someone shopping later in the year might have better luck.

AlaskaErik · July 14, 2021

5 hours ago, steelcity said:

10 speed with the 6.2? What transmission with the 5.3?

6 speed with 3.42 axle. My 6.2 also has a 3.42 axle.

steelcity · July 14, 2021

1 hour ago, AlaskaErik said:

6 speed with 3.42 axle. My 6.2 also has a 3.42 axle.

10 speed vs 6 speed is apples to oranges, no? Even with the same rear gears.

heateyal · July 14, 2021

16 hours ago, American Cobra said:

This^^^^

Also had both. The 6.2 with the 10 speed is near perfection. Others are just fine.

I'd go for it too!

ccoon21 · July 14, 2021

I appreciate y’all’s responses. Looks like I still need to do some research. (Kind of surprised not as many people mentioned the 3.0 considering I’ve read a lot about it in other threads)

I have driven the AT4 (about 95% sure that’s the trim I’ll be going with) that had the 6.2 in it and to say it was fun to drive would be an understatement. I’m just not sure how practical it is for me at this point though.