2013 GMC Yukon XL 2500 - moving up from 2001 GMC Yukon XL Denali

[jsoltren]

[...]backup camera (no more spotter needed to hitch up!)[...]

I spent so much time driving early-2000 model year vans that I can usually get the trailer hitched, solo, on the second try no spotter just looking out the windows, and on the first try if I use trailer alignment poles. But I did really appreciate the camera on the GMT900.

 

[kbuskill]

Do not add LSD additive to your G80.

The G80 in the trucks is a locker.

The G80 offered in the cars was a LSD.

Many people get them confused. GM says not to add the additive to the G80 truck axles.

 

[jsoltren]

Do not add LSD additive to your G80.

The G80 in the trucks is a locker.

The G80 offered in the cars was a LSD.

Many people get them confused. GM says not to add the additive to the G80 truck axles.

Hmm. Maybe that's why I'm having diff locking issues with the wheels cut in my 2001. Local mechanics suggested using the LSD additive. I guess i can flush them and test.

 

[jsoltren]

The second row seats in the GMT900 fold and tumble for stowage. But nothing seems to hold them in place when they're stowed. Indeed, the owner's manual warns that the seats can fall and should be placed in the seating position for driving. That's lame.

Underneath the first row seats, toward the rear, there is a sturdy bar. I think I can secure the folded/tumbled second row seats to that bar using the top tether anchor point and a (very short) ratchet strap. Or, just use whatever cargo I have to keep the second row seats from falling back down.

 

[andy desch]

I had thought about getting a newer Denali instead. There were two reasons why I didn't do this. One was that the Denalis tend to have captain's chairs and I wanted a row 2 bench. (Though, I eventually caved. My 2500 has captain's chairs.)

The new Denalis use the Vortec 6200 6.2L engine that recommends premium fuel and has AFM.

At today's prices we're looking at 1.75/gallon for Regular 87 versus 2.23/gallon for Premium 93 at my local Costco. That's a pretty typical spread.
Source: http://www.austingasprices.com/index.aspx?fuel=C&area=Cedar Park&dl=Y&intro=Y

You *can* run the 6.2L on Regular but it can cause engine issues (knocking) due to the higher compression ratio, and it will result in reduced power output as well.

So I think I made the correct engine choice for my target application, which I'll describe in a future post.

I have a 12 XL Denali and only use 87. I'll maybe use 91/93 if I'm towing my boat somewhere long but rarely.

I have 160,000 with no issues (besides some slow leaking crimps on my engine/trans cooler lines)

 

[kbuskill]

I have a 12 XL Denali and only use 87. I'll maybe use 91/93 if I'm towing my boat somewhere long but rarely.

I have 160,000 with no issues (besides some slow leaking crimps on my engine/trans cooler lines)

You can run 87 but you are leaving some performance on the table if you ever mash the skinny pedal due to your knock sensors detecting detonation and the ECM retarding the timing to compensate for it to keep from burning a hole in your pistons.

As long as you just putt around with it then its no big deal but if that's the case you may as well have a 5.3L... if your not gonna use the 6.2L I would be happy to swap you... lol

 

[swathdiver]

You can run 87 but you are leaving some performance on the table if you ever mash the skinny pedal due to your knock sensors detecting detonation and the ECM retarding the timing to compensate for it to keep from burning a hole in your pistons.

As long as you just putt around with it then its no big deal but if that's the case you may as well have a 5.3L... if your not gonna use the 6.2L I would be happy to swap you... lol

With 11:1 compression on 87, that motor will knock while cruising even. Can't always be heard, especially with the acoustical package that the Denalis have, but it sure can be seen on a scan tool.

 

[jsoltren]

Hmm. In retrospect then maybe it's better that I didn't go for a used 6.2L. If it's been knocking for 100k miles that can't be good for the engine. I hope GM designed their timings so at least this wouldn't cause too much cumulative damage.

The only car i've owned that needed premium was a Subaru with the 3.0L H6, and believe me, I noticed the difference Premium made. Way more torque off the line.

Piston engined airplanes of course use leaded high octane avgas. There is a big effort to find an anti knock additive that is a drop in replacement to tetraethyl lead. If and when that succeeds I bet it will trickle down to automotive applications. Of course, even hypothetical 100LL replacement avgas is super refined, alcohol free, and expensive, so I'm not expecting it to show up at your local Valero any time soon.

 

[97audia4]

Hmm. In retrospect then maybe it's better that I didn't go for a used 6.2L. If it's been knocking for 100k miles that can't be good for the engine. I hope GM designed their timings so at least this wouldn't cause too much cumulative damage.

The only car i've owned that needed premium was a Subaru with the 3.0L H6, and believe me, I noticed the difference Premium made. Way more torque off the line.

Piston engined airplanes of course use leaded high octane avgas. There is a big effort to find an anti knock additive that is a drop in replacement to tetraethyl lead. If and when that succeeds I bet it will trickle down to automotive applications. Of course, even hypothetical 100LL replacement avgas is super refined, alcohol free, and expensive, so I'm not expecting it to show up at your local Valero any time soon.

100ll should not be used on anything with cats.

I ran it in my 100ct tune Jetta as there was small private airport nearby and i could pull up to the pump and out real quick.

 

[gooffeyguy]

My 6.2l loves the 100+ octane E85 I put in it for $1.65 gal

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18