My guess would also be that Mazda's decision to use the Bridgestone tires was based on normal daily driving, probably not so much with Autocross or drag racing in mind (even though a lot of Auto-makers like to flaunt that).. I bought my car with 13,359 miles with the OE Bridgestones. Just from looking at them, you'd have not thought the car had that kind of mileage, they looked very new...I probably put another 400 miles on them before I gave them to the son of a friend and bought me some Kuhmo Ecsta SPT's....

 

The results are still relative to the person driving Pettit's RX-8

Do you think Mazda took into account the wet conditions in the PACNW for us? Uh no because if they did then no way the RX-8 would have ever come with Bridgestone RE40s.

When I replaced the RE40s I had a few goals.

1. Excellent grip
2. Excellent wet weather
3. Decent wear

I did not get everything I wanted. The wet weather performance is significantly improved. The overall grip is really good as well but I do not like the feel of the tires which is the main reason they will be replaced. Obviously this is based on what I consider to be the best. Best for what? Daily driving in the PACNW and not overall ***** out performance.

BTW you should find Pettit's response to the Motor Trend article to know the full story.

 

Fine. then pay 250 bucks a tire for shitty bridgestones that don't work in the rain, squeal like a pig being slaughtered when pushed to the limit, and has half the grip of a tire that uses a decent compound.

My RT-615's were cheaper then OEM replacements and they're better tires. How do I know? Well it's not because I read an article on the intertubes about someone else's tuning experiments, that's for sure. I've owned and used both, and have decided after having real world experience with them, that a RT-615's in a 245/40/18 are sublime, and much better then 225/45/18 bridgestone potenzas. So if someone asks me, I tell them I love my Falken RT-615's in a 245/40/18.

It seems to be to be silly to say "Stock tires are the best because some racing team found that when they fitted tires WAY wider, they ran into some issues." You are completely ignoring the fact that Pettit also fitted other mods to that car that would effect handling, and more importantly, you're also forgetting that there are plenty of wheel and tire combination that do not fall under the "It's as wide a rim as I can fit under the fenders" category.

Come back when you've driven on some non stock rubber so you can make an objective assessment of if it's a good idea to stick with stock rubber or not.

I'm not going to disagree that massively fat tires probably aren't the way to go, but I sure can't agree with anyone who says that OEM tires are the way to go either.


For those of you who are considering RT-615's, Keep in mind that they don't work well when cold (below freezing). They are summer tires for sure. I can only get away with them year round because i live in Northern California, and it almost never gets cold here. I wouldn't push them in rain either, but they're fine for driving around town in the rain, provided you aren't driving like an idiot.

 

What did you replace the stockers with?

 

I can almost assure you Mazda didn't do 100's of hours of testing of different tires to see which was "best" on the RX-8. We would have significantly different stock tires were that the case. Mine came with the Bridgestone Potenza's and I can say I wouldn't put another set on unless there was no other choice. I went with a set of Khumo Ecsta SPT's and have been a lot more satisfied with the handling, ride quality, and road noise than stock, even though they are less than half the price. From reading the forums you will see most people have been much more satisfied with non-OEM replacement tires.

Different people like different handling. In NASCAR while the tires may all be the same for a given track, every car is different on the suspension setup, with some so different another driver would call the car undrivable. If you are satisfied with the performance you get out of the stock tires, then by all means do buy them again, but having to take "multiple sets" of tires and have "professional analysis" of the results to make a decision, no.

 

BFGoodrich KDW2. Please keep in mind this is my opinion and you will find others on the forum that love these tires. But I guess that just supports what I have been saying, the term "best" is relative to the person driving

 

i am confused by the comments about the potenzas squeeling a lot...because from my experience not only do they not squeel, they don't even hardly make a sound even when actually sliding. it's more like a muffled scrubbing noise from my experience.


i find the slip angle very progressive and predictable as well.


225 is not too narrow for a car with zero torque, a very small motor giving a light front end, and an overall curb weight of typically a little less than 3000 pounds.



also, for winter conditions, wider tires are definitely not better, in general. Water gets under them and they slide on top, creating a situation where they develop less grip then thinner tires.

 

I agree wholeheartedly. Good choice.

 

They make tires designed for wet weather that lets water escape much better then the stock tires which enables you to run wider

 

Apparently, you didn't read my post. I didn't say anything about "squealing" I said road noise. They are loud when going down the road, way too loud for a street tire, that is road noise generated by the contact of the tire with the road under normal conditions. I also didn't say anything about running wider, winter conditions, wet roads, etc, I said Mazda didn't test the tires like you were implying they did. If you like the stock size, stick with it, I did, but most people putting on wider tires aren't doing it for handling in the first place.

 

clearly some people think the potenzas squeel....

 

You keep saying OEM is the best tire. The fact is, OEM tire need to consider a lot of other factors with different priorities compare to a driving enthusiast. For example, a lot of us prefer performance, price, and less about tire life and fuel economy.

The OEM tires need to strike a good balance, and hence most of us here may find it not up to OUR standards. Hence the change to 245/40/18.

You haven't tried a Rx-8 with a 245/40/18 set up have you? All you need to do is to change the stock tires to a good 245/40/18 with everything else stock (OEM rim fits 245/40/18 max), go on a track day, and you will see the differences right there.

And YES, OEM tires squeal like a pig being slaughtered when pushed to the limit. The limit for me is TRACK CONDITION.

 

This makes me feel a bit weird as I bought some Re040's from a guy who was selling them nearly brand new for 150$. Also, the Stockers that I have right now are in the bearest of treads.

So for me, the higher rating Potenza's for me were worth it.

 

who the hell designs a car around a specific tire? cars are generally designed around the engine.

the stock bridgestones suck. why do you have to be so obstinate about EVERYTHING. jesus christ.

personally, i love me my toyo T1Rs in 245/40/18. love them.

 

btw, do you if I can run those on OEM rims?

 

OEM 18" rims can fit 245/40/18.

 

How long did all of your stock Bridgestones last before hitting the wear bar or showing metal when replaced (please specify which it was when they replaced?)

 

my bridgestones saw 26k miles before i replaced them. they very between 2/32s and 4/32s of tread depth. only 6k of the miles were mine, during which they saw one 2 day track event (VIR). the previous owner, a pretty attractive lady, used the car for commuting. so 90% were highway miles.

but i've heard of some people getting 20k and the tires are bald.

 

reasons for not stock oem tires:

1. not stock
2. looks better (if going wider, my 255/40/18's killed my wheel well gap a bit, and gives it a meaner look, only had enough money for the rear set)
3. handles better (if right size and compound chosen, i chose a wider better wearing tread, there for i actually lost a bit of grip i had on compared to my stock 225's)

edit: that's 5 years old, and they went with a heavy staggered set up. staggered = fail on our cars. some cars take to staggered, most just for looks. and few are hard core dragsters with skinny mini bicycle wheels in the front and drags on the back.

 

1. well this has the reverse effect on me. I like them better because they ARE stock.
2. width of oem's look perfect for the width/overall design of the car, and seem very appropriate given the car's weight/power level.
3. I am not sure what you mean here...This seems complicated. The word "handle" can mean many many parts of many many things.

 

225s are narrow on an 8" rim.

really, the perfect size for our car is a 245/40/18.

but i'll take your opinion, since you've obviously seen the difference in person.

 

I believe there are two different tire brands from the factory now.

Orginally Bridgestone, and now (Goodrich)?

Anyhow, you probably have run flats. You can swith to a non- run flat to save money and pick up on performance. You won't notice any difference unless you track it.

How ever you may notice a quicker acceleration from tires that signifigantly weigh less.

Remember what run flats are for; weigh your options.

 

Well, technically 8 inches is about 203 mm. 225mm makes sense to have a snug fit, but 245 seems like it would be a bit much, but not by a lot.


I think maybe 235 would also fit well for the size of the wheels

 

all i could think about when i was reading the thread was this same thing. the car wasn't designed or tuned around the tires. the car was built and then tires chosen that would meet the standards of the masses previously given by others (wear, conditions, price, availability, etc.).

 

17 thousand miles before i was down to the wear bars. They also wore down the middle faster then they did on the edges, and I was regularly checking my tire pressure and keeping it at 32 PSI (they leaked more air then my new tires do too). They stunk. The car feels so much better on my 615's. I can give it the beans in a corner and not end up facing the way I came from.

I know they squeal. I've MADE them squeal. I didn't read about it on a website and start waxing poetic about it. I'm over that phase of my youth.


I strongly believe that Mazda went with 225's because they wanted the extra fuel economy a tire with less rolling resistance affords. To compensate for the narrow tire, they went with a soft compound that doesn't last very long to recover some of the lost grip.

To be honest my favorite thing about 245's is that it makes it really hard to curb your stock rims.