Ordered New Tires Already!
 

Yea I'm crazy. So I just ordered a set of 225/45/17 Dunlop Z1 Star Specs for the BRZ. I'm actually going to mount them on my gf's 2010 GTI for a few races until my BRZ arrives. Since I'm #1 at my dealer I'm hoping I only have to run 2-3 events before it comes in. Once the car comes in I'll order some lightweight 17s as well.

Anyone else who is planning to autox this car? What tires are you planning on using?

Hankook RS3, I think the car will be to light for the old Star Specs, although the new Star Spec compound coming out might be a game changer.

Well, if the max 0.75 deg of camber (link) turns out to be true, I don't see much point trying to run real R compund tires and throwing $1k/set away on shoulder scrub.

Since I don't want to go beyond a stock level prep with a DD, I'm looking at a street tire stock type setup. Ideally, I'll get stock size Pilot Super Sports for the stock wheels for DD and wet autox plus something more aggressive on lightweight stock size wheels for dry autox. Right now, I'm thinking 225/45 Yok AD08's. Most tests put these just a bit behind the R-S3's for ultimate dry grip, but they reportedly have stiffer sidewalls and don't need as much camber as the R-S3's. I might even try them for everything at first (DD+wet/dry autox) since they are reportedly pretty good in the rain.

Evil: I hadn't heard anything about the new Z1 SS until you mentioned it - any more concrete info than the stuff here: http://www.azsolo.com/forums/index.php?showtopic=11695 ?

Im gonna be ordering the exact same tires, Star Specs. They work wonderfully on my miata, so it stands to reason they should kick ass on the AS1 as well.

Hello

Which tire is better for "Fuel efficiency / Performance" this is for daily driving
(car will be lowered NOT slammed)

205/50/15 or
195/50/15 or
195/55/15

Thanks

I wouldn't go down any further than the stock 215 width if you can but in theory the lightest tire with the least amount of rolling resistance should be the most efficient. Are you planning on switching to all season tires? If you're sticking with summer just read reviews on TireRack.

I'm assuming he meant for his fit.

you can't have fuel efficiency and performance in the same sentence

a skinny low grip tire on high pressures will yield most fuel efficiency but you sacrifice grip.

driving on high performance street tires hurts your MPG. (although this could be countered by inflating them way above average)

Hankook R-S3 or if they come out with a newer tire, that one. Had great results with my R-S2's and the price/performance ratio can't be beat! Only reason I don't have them on my MR2 is because they only offer 225/45R15's and I needed a staggered setup, so I went with Toyo Proxes R1R, which are also good but more $$.

Yes, this is for the Honda Fit.
I apologize.

In that case, 195/55R15.

I ordered my new tires almost a month ago... 255/?45?/17 RS-3's

I ordered 2 sets, one set is for my S13 track slut (2400lbs 400whp)

when the car comes in I'll get the measurements and order my rims, tires are back ordered til may 20th so I'll have to put the S2K spares on it for the interim i guess....hopefully they fit...

255/45/17s with have a *massive* diameter increase and gearing decrease.

Most of the rolling resistance comes from the hysteresis in the rubber in the tread rather than the sidewalls flexing I believe... Inflating a tire to higher pressure reduces the sidewall flex but can't get rid of the tread's losses. Manufacturer recommendation is usually quite a bit below the rating written on the tire probably for ride comfort or something, and you can gain a somewhat significant amount of fuel economy by going over by a little. An underinflated tire can start to sap a lot of power though.

All that said, rolling resistance usually only accounts for a small portion of energy used by the vehicle, as in the city most of the fuel usage goes to acceleration (and lost to braking), and on the highway aerodynamic drag accounts for more than 10 times as much power as the tires. I think you can get LRR (I believe this means <0.008) rated "performance" tires but not "ultra high performance" or whatever, and I imagine some performance tires aren't that bad in terms of rolling resistance, so using higher performance tires doesn't necessarily cost you that much. Besides, if you can take turns faster in the city you save gas right? :D Materials are improving anyhow and the rolling resistance of all tires are going down.