Pros and Cons of going from 20" wheels to 18"

[DPPWDER]

2017 Tahoe Premier w/magna-ride suspension. It's time for new tires and I'm trying to decide whether to stay on the stock 20" wheels or go down to 18". I live in Colorado and do some mild off-roading. I like the idea of more sidewall provided by the 18's for airing down. Would it also help soften the ride a little? Why is the trend to larger and larger wheels? Manufacturers have gone from 17" to 18" to 20" to 22". Is it for fuel economy? I'd appreciate hearing other's experience and opinions re the pros and cons for each size. Thank you

 

[Big Mama]

I think the larger wheel trend is to mimic the aftermarket (what looks good) and to fit larger brakes. As long as you keep the same overall diameter you’ll certainly see a softer ride. You may want to ensure 18” wheels don’t interfere with any components.

 

[Joseph Garcia]

The trend to larger wheels is mostly for looks, IMO, something that has been successfully marketed to the public. As @Big Mama stated, take a look at existing clearances for brake-related components, and ensure that you have adequate existing clearances to move down to a smaller diameter wheel. If you go to a smaller wheel, try to match the existing 20" wheel offset with the smaller wheel.

I don't off-road, so I cannot advise you in that area, but many of the knowledgeable folks on this Forum do off-road, and they will chime in with their opinions and perspectives.

 

[swathdiver]

2017 Tahoe Premier w/magna-ride suspension. It's time for new tires and I'm trying to decide whether to stay on the stock 20" wheels or go down to 18". I live in Colorado and do some mild off-roading. I like the idea of more sidewall provided by the 18's for airing down. Would it also help soften the ride a little? Why is the trend to larger and larger wheels? Manufacturers have gone from 17" to 18" to 20" to 22". Is it for fuel economy? I'd appreciate hearing other's experience and opinions re the pros and cons for each size. Thank you

The smaller the wheel the more cushion and less curb rash given the same diameter tire. Definitely go down to 18s and run 33s, like a 275-70-18 with a level and you have a pretty capable trail rig! I'd love to do Imogene Pass in my trucks someday.

Just note, the ride may or may not get better with the smaller wheel because the tires are all likely going to be Load Range E and not P-Metrics or even Load Range Cs. LR Cs, offer a better ride but are far from puncture resistant compared with the Es.

 

[DPPWDER]

Thanks for everyone's input. I didn't mention originally that I have installed a 2" Suspension Maxx leveling kit. I was surprised to find out that my spare is on a 17" wheel so I think if the offset is correct I shouldn't have a brake clearance problem with 18's.

 

[TollKeeper]

Wanna trade some Esky 17's for your 20's? LOL

 

[RobH]

As you've discovered, our spares are on 17" rims. No problem for the brakes. The Police Tahoes are on 17" wheels all around.

Why the bigger wheels with shorter sidewall tires? IMO, the larger wheels and shorter sidewalls are probably a fad. Take a look at the wheels and tires on Nascar race cars. And on Indy cars. And on the Police Tahoes.

The 2016 Police Tahoes have P265/60R17 tires which work out to a 6.26 inch high sidewall. My 20 inch tires are 275/55R20 which works out to a 5.95 inch high sidewall. The Police Tahoes have a taller sidewall on a wheel with three inch less diameter.

I'm looking to replace my non-standard 20 inch wheels with as-delivered 18 inch wheels on my Tahoe when I buy new tires.

With your 2 inch lift you could go larger diameter tires on your 20 inch wheels.

FWIW and your off-road ride may vary.

 

[91RS]

If off-roading is your goal then it would be fine. You may or may not get a better ride, that more depends on the tire selection than the size (like Ironman compared to Michelin). You will definitely get more sidewall roll with a taller tire so road handling will not be as good but what is good for off-roading is not generally good for road handling anyway.