Sluggish Tahoe

[David Smith]

Hey guys, I am David and I am new to this forum. Just joined about an hour ago.

I have an 01 Tahoe 4x4. 5.3. 215k on the dash. K&N intake. 3'' lift in the rear with the torsion bars turned up a bit in the front. Larger/wider tires also.

My 'hoe seems to be pretty sluggish at highway speeds (60+ mph). I can be cruising at 80 and even the slightest hill, just to go over a small bridge over train tracks, it has to downshift. When it does downshift, it climbs right back up to 80 without hesitation.

I was towing a trailer a few months back, 6x10 empty single axle, and it would not hold 80mph without having to downshift and run 3400 rpms. It would barely hold 60 mph without having to downshift.

Are these trucks really just that sluggish, or could it be something else? Plugs/wires/fuel pump have all been replaced within the last year.

Thanks!

 

[05alive]

Larger/wider tires also.

Found your problem.
What size tires?

The 5.3 isn't a bad motor but it's not the most powerful offering either. And jacking it up and adding wider tires isn't helping.

 

[David Smith]

Found your problem.
What size tires?

The 5.3 isn't a bad motor but it's not the most powerful offering either. And jacking it up and adding wider tires isn't helping.

285/65/18 Nitto Trail Grapplers on Moto Metal wheels...I never thought it would make that much of a difference.

 

[05alive]

285/65/18 Nitto Trail Grapplers on Moto Metal wheels...I never thought it would make that much of a difference.

That's not that much bigger, you aren't losing much. I was thinking x12's when you said wider lol.

https://www.tacomaworld.com/tirecalc?tires=265-70r16-285-65r18

 

[David Smith]

That is almost 12 lol. They look wider. Probably the offset on the rims...

 

[cmc76]

do you know your gear ratio?

 

[David Smith]

do you know your gear ratio?

I want to say it is 3.23. Pretty high for such a heavy vehicle IMO.

 

[David Smith]

I want to say it is 3.23. Pretty high for such a heavy vehicle IMO.

I need to check in the glove box to confirm that hough.

 

[cmc76]

i am not an expert on gearing. but vehicle weight + those tires. I think you may have found your culprit.

 

[David Smith]

i am not an expert on gearing. but vehicle weight + those tires. I think you may have found your culprit.

That has alway kind of been on the back of my mind. I think that 3.23 is way too high from the factory for a vehicle this heavy anyways. I will check my glove box in a little bit to confirm gears.