Looking to Buy '18-'19 Tahoe Engine/Trans questions

Timbers68

TYF Newbie
Joined
Apr 19, 2022
Posts
22
Reaction score
18
So we're finally close to purchasing a Tahoe except for a couple things.

Choosing between a 5.3 6 speed with the max trailering pkg 3.42 rear gears, or the 6.2 10 speed w/3.23's. Whatever I end up with will be 4WD and hopefully in the 15-30k mileage range.

I have a small amount of knowledge on the 6L80/90 transmissions in stock form, but none on the 10 speeds. I have very limited knowledge about tunes/tuners but have good amount of automotive knowledge and background. I recently test drove a 2020 Tahoe 5.3 w/3.42's and couldn't even feel it shift. Last year my wife and I rented a 2020 Expedition with the 10 speed and same thing: slosh box and it did a lot of whining at idle after several hundred miles (truck had 20k on it). Impressed with the power the Expedition had.

1) If I purchase a programmer (Hypertech, superchips, HP Tuner), is it possible to make either transmission shift firm and be reliable for 100k+?

2) Seems like both engines are reliable, but after test driving a 2020 Tahoe 5.3 w/3.42s, I wasn't impressed with the amount of power it didn't seem to have. I do admit I wasn't putting it to the wood, but drove it like I would my '05 L33 Silverado. Choosing the 6.2 seems like a no brainer except the unknown (to me) reliability of the 10 speed trans. Anyone on here with a lot of miles on a 10 speed? Opinions?

3) Seems like either choice, they get about the same fuel mileage. Those here who have a tune/tuner, does that fuel mileage tend to go up, or down? How much.

At some point I may put an A/T tire on it, no lift, maybe a level lift if they need it.

Thanks in advance.
 

JohnC12

Full Access Member
Joined
Mar 5, 2015
Posts
124
Reaction score
42
Location
Northern Virginia
I really can’t answer your questions since I don’t tune and don’t have a lot of miles on my Tahoe. However, I can make a couple of comments on the 5.3 vs the 6.2.

I owned a 2018 Cadillac Escalade with 6.2 and 10 speed and I thought they paired very nicely. Shifts we’re smooth as butter. However, I decided to get rid of the Escalade because of the rough idle problem I had which I understand is quite common with this motor.

When I was in the market for a new SUV, I knew I wanted to go with the Tahoe with the 5.3. Obviously for the reason mentioned above, but I also didn’t want to have to put high octane fuel in my truck. Based on the fact that you’re looking to tune, this may not be a concern for you, but it was for me.

Overall, I’m very happy with me decision - my 2019 with the 5.3 and 6 speed (4WD with tow) is awesome… zero complaints.
 
OP
OP
T

Timbers68

TYF Newbie
Joined
Apr 19, 2022
Posts
22
Reaction score
18
I really can’t answer your questions since I don’t tune and don’t have a lot of miles on my Tahoe. However, I can make a couple of comments on the 5.3 vs the 6.2.

I owned a 2018 Cadillac Escalade with 6.2 and 10 speed and I thought they paired very nicely. Shifts we’re smooth as butter. However, I decided to get rid of the Escalade because of the rough idle problem I had which I understand is quite common with this motor.

When I was in the market for a new SUV, I knew I wanted to go with the Tahoe with the 5.3. Obviously for the reason mentioned above, but I also didn’t want to have to put high octane fuel in my truck. Based on the fact that you’re looking to tune, this may not be a concern for you, but it was for me.

Overall, I’m very happy with me decision - my 2019 with the 5.3 and 6 speed (4WD with tow) is awesome… zero complaints.
Thanks for this info.

When you say rough idle, like it was misfiring? Guess I need to do a search on this. I haven't seen that concern.

Did you seem to get similar gas mileage between the two?
 

Miami-Dade

Staff member
Super Moderator
Supporting Member
Joined
Dec 8, 2016
Posts
2,896
Reaction score
2,427
I have a 2016 Tahoe LT with the 5.3 2 WD.

I have a 128K miles on my Tahoe. The 5.3 has enough power for me. I drive from Miami-NYC several times a year and can keep up with anything that is out there on the highway. I run 87 octane [mostly Exxon-Mobil] since new.

The 2018-2019 are good years to get. Some of the 2015-2017 had A.C Condenser issues and Brake Booster issues. I would shoot for a 2019 even if it had slightly higher miles.

I get slightly rough idle here and there but nothing to annoy me. I had several rental 2015-2016 Tahoe-Suburban before buying one and they all did the same thing.

As far as a tune goes was thinking of getting a Black Bear Performance tune. Everyone here who got one loves it.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
17,108
Reaction score
21,716
Location
Stockton, Ca.
It really boils down to what you want
the 6.2l has more power, yet slightly lower towing capacity with the gear ratio
the 6.2l will get slightly lower mpg as well, but has a nice trade off with more power
the 6sp and 10sp should both be fine in that year range, you don't have to feel the gears bang for it to work good, but it can be tuned that way.
a tune will help a lot in either case
@BlackBearPerf
 

JohnC12

Full Access Member
Joined
Mar 5, 2015
Posts
124
Reaction score
42
Location
Northern Virginia
Thanks for this info.

When you say rough idle, like it was misfiring? Guess I need to do a search on this. I haven't seen that concern.

Did you seem to get similar gas mileage between the two?
Exactly... like it was misfiring when at idle... at speed, there were no issues. I was constantly cleaning my throttle body which would, for a short time, take care of the issue. But without fail, it would start idling rough again. I'd swear she ran better after an oil change, but that was probably just in my head. Other's have reported broken motor mount as the culprit. There's a laundry list of suspected reasons, and quite frankly, I didn't want to deal with the stealerships so I just sold it. Google 6.2L rough idle and you'll find tons of good stuff on the issue. Oh wait... just do a search on here... plenty of posts on here about the issue. ;)

I saw slightly lower gas mileage with the 6.2, but like Doubeleive mentions, there's a bit more pep as compared to the 5.3. If you're worried about MPG, I'm guessing you'd prefer not to spend more on gas? If so, don't forget that you have to put 93 octane in the 6.2, or it will run rough.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
17,108
Reaction score
21,716
Location
Stockton, Ca.
the "general" fix for rough idle is to keep the intake clean and put injector cleaner in it either as needed for a few tank fulls or on a regular basis as a routine, I add 2 bottle's per full tank of gas to my vehicles at least once every 3 months, sometimes more often just depends on when I remember to do it, I buy the stuff from walmart by the dozen it's only about $1.25. Other options would be a injector service.
 

JohnC12

Full Access Member
Joined
Mar 5, 2015
Posts
124
Reaction score
42
Location
Northern Virginia
the "general" fix for rough idle is to keep the intake clean and put injector cleaner in it either as needed for a few tank fulls or on a regular basis as a routine, I add 2 bottle's per full tank of gas to my vehicles at least once every 3 months, sometimes more often just depends on when I remember to do it, I buy the stuff from walmart by the dozen it's only about $1.25. Other options would be a injector service.
I had a fundamental problem buying a $90k (my MSRP was $89,525) Escalade only to have to clean the TB and MAF on a regular basis. And on top of that I have to put injector cleaner in a brand new vehicle? Now way! And lets not forget that it's a royal PITA to get to the TB. Unacceptable in my opinion.
 

Forum statistics

Threads
118,757
Posts
1,633,777
Members
79,765
Latest member
Jocko
Top