What sizes work with the standard wheel? I was thinking maybe something a little wider like 245 (which I think is max or 8in wheel), with either a 50 or 55 sidewall. Also, what performance tires have you gone with? I want to go with something with a little more grip and more aggressive looking, but like the OEM wheel and want to stay with it.

 

I wouldn't push much past the 235 width on the current rim, most application that use this size often use an 8" wide rim the RDX is only 7.5"

You may want to check out the tire rack it may be possible to find a wider rim significantly reduced enough to really make it worth wild to look at other tire sizes.

The other option would be to run a narrower 225-60-18 tire on the OEM rims. But if performance is the key option here I would stick with a 235w and look for something like a summer only tire in that size.

Yokohama ADVAN series and Pirelli Scorpio brands both have summer only tires for the RDX.

Else the only other real option is step up to some 19" rims and a 245-45-19 tire. Tire rack has quite a large selection of rims for under $200ea. But at that price it may still be a better option to replace the OEM Pilot again. And I'm really not all that upset with them, I wasn't too thrilled with them on the FWD TSX, but they seem to work very well on the SH-AWD RDX. And the wider size may help.

 

Ok, I did not realize they were 7.5in wide, figured they were 8. I guess I will stick with the 235 width then. There are not a whole lot of options at the 235/55/18 size, I wonder why Acura chose such an odd ball tire size.

 

I think most OEMs choose sizes for durability and diameter ideal for the drive train. 215-50-17 on the Accord V6 and TSX was an uncommon size for some time, but many other OEMs adopted that size and it's a lot more common now. Mazda and Toyota use it now as well so the selection has improved.

Also I think the OEMs work directly with tire mfg.s on new cars so the tires that come on your car may have been designed right out of the box in a custom size for X OEM.

I've noticed that more and more choices are showing up as the months go buy. In a few years the size should be a lot more common as more and more cars needing this larger size will need replacement tires. Even other luxo-sport-crossovers may adopt this size too.

If you can get away with Summer only tires their are several I would look at, Continental, Pirelli, and Yokohama as I said before. Ours lives in a snowy winter area so I'm going to look for performance all-seasons if I can to avoid having a second set of snow rims like I have for our TSX. I'm going to run out of garage space if every car has 2 sets of rims. With the SH-AWD I hope to get buy in the snow with A/S tires and some patience when it snows, else drive the TSX and Dunlop Winter Sports.

 

https://acurazine.com/forums/showthread.php?t=1808

Check post #4. 13,000 miles so far, excellent wear and performance.

 

Bleu, you put 255 on stock rim? If so, does the sidewall look right?

 

The sidewall looks perfect, both outside and inside. Not enough bulge to protect from curbs, but also not flat from rim to pavement like you see on a TL. Big improvement in steering response, grip and more quiet than the stock rubber.

 

Do you have any pics you can post up? I'd be interested in using these tires when I replace the factory ones.