Which Indy 500 tire size for new 19" wheels?

I'm currently running factory 235/50/18 P Zero's on my 2016 GT Premium. New 19 x10 wheels are inbound! I've decided on the Indy 500 thanks to the great information on this forum. Now my question is what size? I initially thought 285/35/19 for a strong squared look, but I keep reading that ride comfort is affected by sidewall height "aspect". Now I'm contemplating 275/40/19 for better ride quality? I'm on the factory suspension with zero modifications, although that may come soon. My primary goal is ride comfort as this is a no track, spirited 2-3 x week driven car. I look forward to the forum members and experts recommendations.

275/40R19 may be just a tiny bit more comfortable, but the 285/35R19 offers quite a bit wider tire overall (0.8" more tread width per tire), and is a perfect fit on a 10". The Indy 500 ride very well in both sizes, so I wouldn't worry too much.

For the 19x10 go with the 285/35/19. I don't think you can even get them any bigger than that for 19" wheels. 275 will probably have a small stretch on 19x10 and that won't make the ride quality better, but the 40 sidewall might compensate for that though minimally.

I would do 275/40/19 to fill up the wheel gap a little better if you are not planning to drop your car.

I run 285/35-19 on track-stiff springs and the ride comfort is fine - plus yours would probably be a wee bit better as you have a 10" wheel vs. my 10.5" wheel giving you a little more vertical sidewall (mine has a "just barely beginning to stretch" kind of look, which I prefer). Granted, it's better when I run my A/S tires on the stock wheels which are 40 aspect, but... 35 is fine.

30 will net you a real difference. I have 30 aspect track tires... that I notice if I have to drive to the gas station (which is like every other damn session because this fuel tank/pump design sucks).

285, they're a bit soft in sidewall, listen to BmacIL.

Both sizes work fine

275/40/19 & 285/35/19

Just installed a set of the LMR 350R wheels yesterday with 285/35/19 Indy 500 tires

Thanks to all the replies. It would appear my concerns related to ride quality between the 285/35 vs. 275/40 tire sizes is nothing to worry about. I actually enjoy the quality of the ride on the factory 235/50 tires but look forward to the appearance of the incoming new wheels/tires. I'm glad to hear moving to either of those larger tire sizes will not have a negative effect on the ride quality.

flyinghunter said:

Thanks to all the replies. It would appear my concerns related to ride quality between the 285/35 vs. 275/40 tire sizes is nothing to worry about. I actually enjoy the quality of the ride on the factory 235/50 tires but look forward to the appearance of the incoming new wheels/tires. I'm glad to hear moving to either of those larger tire sizes will not have a negative effect on the ride quality.

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The overall weight will make more of difference in ride. The factory 18s weigh 25 lbs. If your wheel and tire combo isn't much heavier you will mostly get a handling improvement without much, if any ride penalty.

I just went from 8.5/10" rims with 255/40R19 front 275/40R19 rear pirelli p zero's to 10/11" rims with 285/35R19 front and 305/35R19 rear Nitto 555 G2 tires. The new set up feels better than previous. The height of the sidewall is an aspect ratio of the width. I think the difference in sidewall height was something like a 10th of an inch between old set up and new. Use the tire calculator to see the difference. Picture of new set up 7 spoke with 285/35R19 front. Compare to old set up 5 spoke with 275/40R19 rear. Hope this helps.
https://tiresize.com/calculator/

Paul@PKAUTODESIGN said:

Both sizes work fine

275/40/19 & 285/35/19

Just installed a set of the LMR 350R wheels yesterday with 285/35/19 Indy 500 tires

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I almost did the Firestones. They could easily get 285/35R19 but the 325's had to be shipped and they wanted $40 a tire for shipping. I passed and did the 555's. I have read a lot of good things about the Indy's.

275/40/19 on 10" square.
20170216_123610 by chefjpd, on Flickr

I just installed these yesterday in 285/35/19 on 19x10 wheels from www.oewheelsllc.com. These will be my street wheels so I can free up my Forgestar c5 18x10 for sticky track tires.