285/35/20 vs 285/35/19 RE-71

I'm about to pull the trigger on my track day wheels/tires and torn between 19x9.5 with 285/35/19 vs the 20x10 with 285/35/20. Both combos will run the RE-71R.

The shorter wheel/tire will likely have slightly better turn-in due to less weight/height. The taller tire will probably be less prone to getting greasy and probably slightly better absolute lateral grip.

The difference in gear ratio has both advantages and disadvantages for either setup.

As far as looks... it's a wash, IMO. Is the 19" really going to be any more robust vs potholes compared to the 20?

I'm thinking the 19 would be a better AX combo, while the 20 would shine on the road course.

Am I missing anything? Resale value? OCD mental gyrations over nothing? :headbonk:

Planning on hitting TrackDaze at VIR at the end of March. Then a cozy event we do in Memphis every year in May.

I wouldn't run 20's for a track setup on this car. A 35 aspect tire is not going to have an issue on the track at all, and there are benefits to be had from a taller sidewall too. 20's = heavier and that mass is all further out, so worse inertia (worse acceleration, slower response, worse braking). I also would run a different tire than the RE71R for track use. It's designed to heat up fast and will get greasy much easier than a more track-oriented tire, vs. auto-x tire. Hankook R-S4, Star Specs, RE11's, or if you can spring for them, Sport Cup 2's would be better options.

BmacIL said:

I also would run a different tire than the RE71R for track use. It's designed to heat up fast and will get greasy much easier than a more track-oriented tire, vs. auto-x tire. Hankook R-S4, Star Specs, RE11's, or if you can spring for them, Sport Cup 2's would be better options.

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Thanks for the input. I ran the star specs on my last ride, and they are hard to kill. Noisy as hell, but did great on track. Problem with the Direzzas, R-S4 is that they don't make them in 285/35/19 or 285/35/20 for that matter. Ford kind of hosed us up with these oddball 275/40/19 PP wheels/tires... finding something that is close in height is a real challenge. What about the Rivals?

Could get a set of Pilot Super Sports which are made in compatible sizes... but figure even slightly greasy RE71s would do better on track.

BTW, I don't do any road course events in the summer... early May will be my last track event until the fall.

lugz said:

Thanks for the input. I ran the star specs on my last ride, and they are hard to kill. Noisy as hell, but did great on track. Problem with the Direzzas, R-S4 is that they don't make them in 285/35/19 or 285/35/20 for that matter. Ford kind of hosed us up with these oddball 275/40/19 PP wheels/tires... finding something that is close in height is a real challenge. What about the Rivals?

Could get a set of Pilot Super Sports which are made in compatible sizes... but figure even slightly greasy RE71s would do better on track.

BTW, I don't do any road course events in the summer... early May will be my last track event until the fall.

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Rivals and RE71Rs are very similar in those regards.

RE11 will be great at the track. Not nearly as fast as the RE71R over a lap, but durable (and streetable too). They are a class above the PSS in grip, but still reasonable for street and wet use.
https://www.tirerack.com/tires/tire...wall=Blackwall&partnum=835WR9RE11V2&tab=Sizes

You mention 19X9.5s. I run 19X10s and love them. I am currently running RE71s and like them a lot. I have run other tires on these rims and wouldn't want anything narrower for the 285/35/19s.

Just my $.02 worth...

<TED>

tedj101 said:

You mention 19X9.5s. I run 19X10s and love them. I am currently running RE71s and like them a lot. I have run other tires on these rims and wouldn't want anything narrower for the 285/35/19s.

Just my $.02 worth...

<TED>

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I'm with you... I'd run 19x10 if they made the wheels in that size (TSW Bathurst). :frusty: Hearing about the autox folks running the RE71 on even narrower wheels makes me feel OK about it. Other tires with soft sidewalls certainly wouldn't do as well.

A wider wheel is more ideal. That said the photos of my car cornering under load with the 275/35R19 RE71R on stock wheels (9" and 9.5") and the sidewalls are still pretty squared up to the road. Damn stiff they are. Why not look into a different wheel though? Seems like 9.5 really limits you down the road.

As for heat, they don't really get all that greasy. At the last track day on nearly bald, year old RE71Rs and we did notice my car getting a little looser in the rear toward the end of the sessions. I think I was into the harder secondary rubber on the shoulders of the tire and it migh have had something to do with air pressure. When the tires were younger I never noticed grip dropping off late in sessions, and even if they were, they were still faster than MPSS tires. They will show heat rippling if used at the track.

For track wheels, I'd be looking at 19x10, 10.5 or 11, and yeah no reason to go to 20, although some sports cars will run 30 profile tires from the factory and they do fine.

NightmareMoon said:

Why not look into a different wheel though? Seems like 9.5 really limits you down the road.

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Thanks for all the great input guys! Yeah, believe me I've toiled over the wheel selection. I wanted the best value on the price to weight curve. My 2nd choice was the SVE GT350 19x10 which is a pretty amazing deal for the weight. The Bathurst is a bit more expensive, but is a good bit lighter. Bathurst does come in a 19x10.5, but that seems overkill for a square 285 setup.

10.5 is perfect for a 285 square setup and would be wayyyy better than the 9.5

As others have said 19x10 if it is in your budget. If you are stuck on 9.5" wheels running a 265-35 RE71R would fit the 9.5 much better also saving you 3 pounds at each corner which is substantial. Not saying a 285 would not work but it would be better on a 10-10.5" wheel.

Optimum Performance said:

As others have said 19x10 if it is in your budget. If you are stuck on 9.5" wheels running a 265-35 RE71R would fit the 9.5 much better also saving you 3 pounds at each corner which is substantial. Not saying a 285 would not work but it would be better on a 10-10.5" wheel.

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Hmmm... looks like a nice selection of tires available in 275/35/19 ... RE71, Direzza, RS-4, etc. Could stick with the 19x9.5 wheel then.

So then it would be a 19x10 SVE with 285 vs 19x9.5 Bathurst with a 275. Would the heavier SVE (by ~3lbs) be worth being able to run the 285?

The AutoX guys that are running 285s on a 9" rim with 5mm spacer are doing so because of the rules for the stock class. I am running 19x10 with a 275/35 and 19x11 305/30 (different AutoX class) and am happy with the results. With the stock suspension I have clearance and a spacer is not needed. Have you looked into 18x10s, there are a lot more tire choices and the smaller overall diameter gives a bit less weight and a little more wheel torque.

Some tires don't suffer as much being "pinched" on narrow wheels. Usually it is tires with a stiffer sidewall. That being said 9.5" wide is the minimum spec for most 285/35/19 so it really isn't a bad setup with the right tire. I recommend the 285/35/19 RE71 as they have a stiff sidewall and great grip.

lizardman said:

Have you looked into 18x10s, there are a lot more tire choices and the smaller overall diameter gives a bit less weight and a little more wheel torque.

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I was excited to jump on the recent Apex group buy, but couldn't find any 200TW tires even close to the stock 275/40/19 height. IIRC they were are 26" tall or shorter. This whole process of finding the right wheel/tire sure is a PITA.

I failed to mention the Memphis event we do every spring is sort of an iron man event - we do road course, auto-X (more like a mega-cross) and some drag strip passes. The combo really needs to be a good compromise for all of the above.

295/40-18 Hankook RS4 is a good match to the stock diameter. Only issue is 295 is where fitting up front starts requiring significant attention.