Tire size for a 4" lift

Hi
I have a 4" BDS lift on my 2009 Tahoe and will be shopping for tires soon.

I have Michelin Defender LTX M/S 2 in 285/70R/17 on 17x9 wheels. According to the spec on these tires they are supposed to have a height or diameter of 32.8" But using a level and a ruler, I measured 31.5". I really don't believe I have lost that much rubber over time (got them in 2019) and maybe put 20-30 k miles on them so thinking they were manufactured smaller than spec - tread depth is still good and has not reached the indicator yet. I can fit into my garage (barely, have an 1.5" to spare). But know if I go taller, I may have to sacrifice getting it in the garage

Anyway, I want to go with a taller tire and want to know how big I can go. I don't want to go wider.

With all of you who have a similar lift, what tire and tire size are you running?
Are you able to park in your garage? If so, what is your garage opening height?

Anyway, hope you all can give me some ideas to consider.

I just did 275/6/20 on factory wheels. I went with the Cooper Strongarm. Amazing ride

I think @Tozan runs 34 inch tires on his 4 inch lift and it looks good

I am running Goodyear Territory MT's now 315/70R17 they are about 34.5 tall and 10 in wide. Good tires in wet snow and sand. Low noise and smooth.


I was running 35's before they were 34.6 tall and 12 in wide. The narrower 315/70R17 give me better traction and slightly better MPG.

If you are going to run taller tires you will benefit from re-gearing it, or deal with slow acceleration and terrible MPG... I would recommend 3.73 and no more than 4.10s

Also if you go to 34's you might need to trim a few things to keep them from rubbing near full lock.

Tozan said:

I am running Goodyear Territory MT's now 315/70R17 they are about 34.5 tall and 10 in wide. Good tires in wet snow and sand. Low noise and smooth.


I was running 35's before they were 34.6 tall and 12 in wide. The narrower 315/70R17 give me better traction and slightly better MPG.

If you are going to run taller tires you will benefit from re-gearing it, or deal with slow acceleration and terrible MPG... I would recommend 3.73 and no more than 4.10s

Also if you go to 34's you might need to trim a few things to keep them from rubbing near full lock.

Click to expand...

Do you think my factory 3.42 is reasonable for 33" tires?

Charlie207 said:

Do you think my factory 3.42 is reasonable for 33" tires?

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I personally never tried that combination.. So someone else might be better to answer that question. 3.42 with 34.5 inch tires does not work well at all.

Tozan said:

I personally never tried that combination.. So someone else might be better to answer that question. 3.42 with 34.5 inch tires does not work well at all.

Click to expand...

What are your personal parameters for "not working"? I'm feel like with the 5.3 it wasnt ever too doggy around town, and cruised fine on the highway. The 5.3 never really impressed me with huge power/torque, but the 6L80 did fine after he BBP tune.

I noticed less shifting after the 6.0 swap & new torque converter (possible the TC has nothing to do with anything), and just assume the stronger engine now has less struggle to move the rig.

I'm probably not going any larger on tire size, but have a spare front differential (bad bearings) sitting around, and have played with the idea of regearing it, then the rear of my rig.

Is there an online calculator to compare tire size/transmission ratios/final drive that you know of?

Charlie207 said:

What are your personal parameters for "not working"? I'm feel like with the 5.3 it wasnt ever too doggy around town, and cruised fine on the highway. The 5.3 never really impressed me with huge power/torque, but the 6L80 did fine after he BBP tune.

I noticed less shifting after the 6.0 swap & new torque converter (possible the TC has nothing to do with anything), and just assume the stronger engine now has less struggle to move the rig.

I'm probably not going any larger on tire size, but have a spare front differential (bad bearings) sitting around, and have played with the idea of regearing it, then the rear of my rig.

Is there an online calculator to compare tire size/transmission ratios/final drive that you know of?

Click to expand...

With stock tires I would agree that gearing works fine. I am hoping your comparison of your 5.3 is with 35 tires other wise there is no point to your question. My rig is not a street queen and gets some pretty hard off road use and gearing makes a big difference.

But, to answer your question assuming you were running 35's. MPG dropped down by 8 mpg and acceleration was pretty sluggish, off road performance was not very good and on steep pulls or rock crawling it would sometime fail to pull.

Tozan said:

With stock tires I would agree that gearing works fine. I am hoping your comparison of your 5.3 is with 35 tires other wise there is no point to your question. My rig is not a street queen and gets some pretty hard off road use and gearing makes a big difference.

But, to answer your question assuming you were running 35's. MPG dropped down by 8 mpg and acceleration was pretty sluggish, off road performance was not very good and on steep pulls or rock crawling it would sometime fail to pull.

Click to expand...

My question was about your opinion on if a re-gear for 33" tires was worth it. Sorry for the confusion. You seem like you have some real-world experience with larger tire sizes and performance/characteristics.