Very disappointed with up-hill performance

[Markov]

So I was taking my 04 Yukon XL 1500 across the grapevine from LA to SF with no trailer just the 4 of us and our sleeping bags ect.

I thought it would be an easy trek for my GMT800 but nope! I was struggling going up the interstate 5. I mean I had small cars and mid sized so called SUVs pass by me like it was nothing....


Can someone please explain why my car was so damn weak going up the mountains?

 

[Rivieraracing]

Gotta give more info, motor size, tire size, mileage, etc!!

 

[Martinjmpr]

I noticed the same thing the first time I took my '04 Suburban up Mt. Vernon Canyon (the steep portion of I-70 that heads West out of Denver.) I'm assuming your XL has the same 5.3 as my 'Burb.

Personally I blame the rather lackluster climbing ability on the transmission. It's set up so that it waits until the engine is really lugging before it downshifts. It's almost like it HATES to downshift, the only way you can get it to downsift automatically would be to really stomp on the gas.

One solution is to manually shift down to 3rd or even 2nd depending on speed to keep your engine speed up. It's a real shame they didn't think to put a 5 or 6 speed automatic on these trucks, they would be much more pleasant to drive, but if you want the 6 speed you have to wait until the 2009 (GMT-900) models, sad to say.

Another solution is to put it in "tow/haul" mode. I believe this will make it downshift sooner when climbing a hill.

The 'Burb is my first V8 since the 1971 Blazer I owned from 1983 -85 so to say the least, I was disappointed in its performance. On the plus side, I'd say the 5.3 is pretty "over built" for the amount of performance it puts out in stock form.

 

[YukonandtheHOE]

What last poster said, When coming up to long grades hit the Tow/Haul, it prevents the TCC from locking up (overdive)