Why do the later 900's feel like slouches compared to the early ones?

[91RS]

I've been pining after a GMT-900 Yukon Denali or Escalade for a while now. I conceded and bought a 2007 SRX 3 years ago because I felt like I was getting a lot for my money but I wanted a full-size at the time and I still do. I'm still not sure if now is the right time to get out of it especially since I've spent a bunch of money on it this year "restoring" it because we said we were going to keep it longer. I don't want to get to the point where its worthless even selling private party and the only place I can find a 900 is at a crappy buy here pay here (where so many of them already are). Anyway, with the unnecessary backstory out of the way, on to my question.

I've driven a lot of these over the years but until I started wanting to buy one, I never noticed this. One of the tests I like to do is time acceleration from 60-80. Some of the ones I've timed: 2007 Yukon XL 5.3L, 2012 Tahoe LTZ 5.3L, 2013 Yukon Denali (I think it was AWD, can't remember now), 2012 Yukon Denali XL AWD. The 12 XL was the slowest but the Tahoe and 13 Denali were about the same and the 07 5.3L XL was a little faster than all of them. I know the 07 had 3.73 rear end gears and the 4 speed. Is this all in the gearing (trans or rear end)? Maybe GM trying to get these trucks to have better fuel economy? Is it torque management where a tune would "fix" it? I thought maybe it was the 6 speed trans but even my SRX with the Northstar doesn't feel nearly as sluggish as the later 6.2L trucks. I haven't had the opportunity to time a 07-10 pre-AFM 6.2L yet.

 

[Matt_]

I think it's a combination of gear ratios and tunes. The older trucks with 3.73s and 4speed transmissions had no choice but to bump RPMs when you hit the throttle on the highway, since one gear was a huge jump.

The newer trucks already run lower RPMs due to normally having higher final drive ratios, plus more high gears to fine tune cruising at speed, so they need to jump 2 or 3 gears to really accelerate.

FWIW I noticed the same thing on my truck which is a 2012 L96 6.0 with 6L90E and 3.73s. Accelerating to 60 was fine, but it would fall flat on its face for some reason. And if I was cruising anywhere above 50 and wanted to pass, it just wouldn't go.

.....then I got it tuned by Black Bear Performance. Now it accelerates STRONG to 90 (itll keep going but that's where I've stopped my data logs). Starting from a slow roll or 60mph doesnt matter. Now when I push that skinny pedal, it immediate finds a good gear and takes off like an overweight rocketship, and keep gaining speed till I tell it to stop.

Get a new(ish) truck and get her tuned, you won't regret it

 

[drakon543]

alot of gm vehicles 05 and newer have horrible torque management curves. like on my 07 g6 if i caught it at the right rpm and speed range it would launch like a rocket. outside of that it felt like it was just dogging it. most tunes will turn that feature down or remove it all together. im sure blackbear takes this into its tuning.

 

[swathdiver]

^^ What Matt and James said!

Modifying Torque Management and tuning the transmission makes these trucks drive completely different from stock.

 

[91RS]

I know about the torque management. I just wanted to make sure that was mainly what it is before assuming a tune would make it better. I had a remote tune done on our 2007 SRX (RWD, N*) when I put the 20" wheels on it to correct the speedometer so I'm sure that modified the torque management on it. The SRX is around a second faster 60-80 than the 13 Denali with an 80hp deficit but also 1000 less pounds of mass.

I found a 2009 Escalade about 2.5 hours away I was wanting to go look at but it spent 3 years and 26k miles in Michigan so I'm scared of the rust. It sucks because it's blue with black interior like I've been looking for (I'm ok with any color that isn't white, black, or gold with a black interior). I want to own this truck for 10+ years if I get rid of the SRX (which isn't is bad shape). I've found a couple real nice 12-13 trucks but my wife doesn't want to spend that much.

 

[Doubeleive]

I have a 2012 xl Denali and it's no slouch, lol I would say do you test again but this time drop it down a couple gears so your not getting any torque management other than your foot and see how you like it, a good tune will probably give it a faster kick down response then stock. (like having a shift kit).

 

[gpracer1]

After a tune and relearning shift patterns my 13 LTZ is a beast. It’s relatively quick and 60-80 is impressive......and I drive a vette.

 

[swathdiver]

I found a 2009 Escalade about 2.5 hours away I was wanting to go look at but it spent 3 years and 26k miles in Michigan so I'm scared of the rust.

I bought a 2004 Pontiac several years ago that spent most of its life in Wisconsin and there is no rust on the body, surface rust on the frame, but some of the thinner pieces like the spare tire hoist were pretty rusty, sprayed it all down with oil and forgot about.

My truck spent seven years in West Virginia and there is no body rust, just some rusty bolts underneath and surface rust on the frame. It's been a year now and it's no different. Sprayed with oil again.

Take a drive and check it out. Mine was 700 miles from home.

 

[adventurenali92]

My 2006 spent its first 9 years of life living right near the Pacific Ocean in Newport Beach. Only minimal surface rust, nothing to really worry about. So don’t be afraid of a Michigan truck. Go look at it! I only traveled 2 1/2 hours from where I live to end up buying mine. But I was willing to travel 6-8 hours for the right truck that I was looking for. So don’t let a far away truck keep you. It can pay off in the long run if it’s the right truck for you!

 

[Doubeleive]

if it's meets the specifics of what your looking for I say go for it, I flew to get mine and drove it 7 hours back home