03 Yukon SLT / Suggestions on performance please!!!!!

[screamin86]

Which gears does yours have? I know some came with 3.42s but I think it's kinda rare most had 3.73s or 4.10s. These 5.3s have more upper end power though mine comes on strong aroun 2800rpm.

here is the pic of my buddy towing my yukon.

 

[hoe]

I tow anything with my Tahoe. I towed my 85 burban across the united states of America, on a uhaul tow dolly. Even pulled hills up to 100mph making passes. Granted I had a 6.0 and a 80e tranny in there. I have towed with the 5.3 and It will pull as well.

The OP has something terribly wrong with his truck, thats why I told him get the CEL off 1st.

You want performance then its many things you can do.

My 01 Tahoe has a:
6.0 Vortec Max engine LQ9 (LQ4 is in the 2500 trucks)
LPP longtube headers, with 3" ORY pipe
Airaid Cold Air Intake
4L80e Transmission Heavy Duty (2500 or 3500 trucks)
4000 RPM Torque Converter, 9.5" billet
4.88 gear ratio, trutrac limited slip
232/238 speced cam compared to a stock (196/198)
plans for a intercooled procharger, when all is said and done.

 

[screamin86]

whoops i didnt see about the ses light on. check the codes or see if you can hook up a scan tool that would be better that way you can see whats going on a little better.

 

[M3PO]

Big wheels will make a difference, try your 20s. I have the factory 20s on my Denali and I thought about trading someone with some of the smaller Denali wheels (I think they are 16s), but I have seen them so cheap, I think I will buy another set.

 

[hoe]

Big wheels will make a difference, try your 20s. I have the factory 20s on my Denali and I thought about trading someone with some of the smaller Denali wheels (I think they are 16s), but I have seen them so cheap, I think I will buy another set.

Forgot to add Im also 20 x 9 rim, with 305 50 20 tires. Which is actually a 32x12
This is why the right GEAR needs to match the right tires. With 20s, 3.73-4.10 is fine with under a 31" tire, some people will even recommend 4.30s. With 33"-35 4.56-4.88 gears.

Im running 32" tire with 4.88s, lots of leverage there, and tire burner. I am highly over-geared. Which comes with negative and positives. It comes down to how and what you use your truck for.

 

[big_b_in_PA]

Big wheels will make a difference, try your 20s. I have the factory 20s on my Denali and I thought about trading someone with some of the smaller Denali wheels (I think they are 16s), but I have seen them so cheap, I think I will buy another set.

I don't want to thread jack but, m3po if you were closer I'd take you up on trading wheels.

 

[UBILLN]

gearing is your main concern when towing a load, of course mileage is going to suffer when your not but unless you like changing gears in between tows, there's not much else you can do. An intake & exhaust might help a bit, but not enough to make a significant difference.

Oh and yeh if your running bigger wheels/tires than what it came with stock, then thats going to cause problems when towing too becuase you are messing with gear ratios.