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[britt_e82]

Just curious if anyone has had this issue.

I just recently replaced the factory Bridgestone runflats with Bridgestone RE760's.

To get the RE760's I had to go up a size from the stock 215/40/18, 245/35/18 to 225/40's and 255/35's.

I hate the way the car feels now. My car is bone stock and I love it. The new tires have a ton of grip but the handling is sloppy and the car just feels more sluggish.

Can the slighly bigger tire have that much effect?

Is in the softer sidewall creating the sloppy feel?

My car just feels completely different. It's really depressing. I'm going back to the tire shop tomorrow to see what my options are.

Any one else have these issues?

[ptack]

What year is your car? I can't imagine why you would find normal tires worse that the run craps, especially if they were 1st year Bridgestones. Depending on how long you were driving on them, it could just be the simple fact that you got used to the run flats. When I got my car I drove on the runcraps for all of about 30 days until I put a set of Dunlop Winter Sport 3Ds on. The Dunlops were a noticeable improvement even though they were snows. It might be remotely possible that your new tires are not good to use for a +1 size increase, but the change in geometry for the tire is pretty small.

Since you say it feels sluggish, I would guess that you're just not used to them because the new tires should each be about 5 pounds lighter which technically means you car will accelerate slightly faster.

[BMW86]

I think maybe you made a poor decision in tyre choice. I'm EXTREMELY happy switching to non-rft's.

[britt_e82]

My car is an 08. Sluggish is probably not the best word. Still has plenty of power. It just isn't as stiff, and I really got used to the old feel. I've never really noticed any significant rolling when cornering and sloppiness on the highway until now. It reminds me of a 328 I got as a loaner when my car was in for its 30,000 mile service a few weeks ago. I probably just got used to the stiffer sidewall.

What should the tire pressure be on my setup? Could that be an issue? I haven't physically checked it but the paper work from the tire company states 32lbs. and door sill sticker states 36lbs.

[sb335is]

you didnt get the right tires....... ha
should have gotten some hankooks or yokos

[ErvGotti]

Originally Posted by maxnix

RE760 is a passenger car tire. You should have gone to something like a Pole Position RE050a. You got bad advice. Read the tire tests at www.tirerack.com at the minimum!

+1 get yourself some performance tire's

[old1]

The RE760 is classified as an ultra high performance summer tire, so it should be good enough for the street, although admittedly not as stiff or sticky as the next level up max performance the car came with. When I switched to non-RFT's, I went with Michelin Pilot Sport A/S (can't justify the time/trouble/expense of winter tires down here, but wanted better cold weather performance--and ride) I noticed much less harshness and improved ride on our nasty city streets, but I also noticed much sloppier handling at high speeds out on the road. Made sense to me because having softer sidewalls is like switching to softer springs. So I upgraded to the BMW Perf. Suspension and it really did the trick. I'm running 37/39 PSI front/rear and really love the responsive cut and thrust of this setup.

[britt_e82]

"Old1" Thanks for an honest reply. I realize why I seldom post on forums when I get short responses like "you bought the wrong tires ... ha"

I did a great deal of research before purchasing these tires. I specifically wanted a longer lasting harder compound, quality tire. I will never track this car. It's primarily my wifes car that I get to play with on the weekends. I have a friend who has a 911 Carrerra 4S who goes through a set of rears once a year and swears by the 760's for there quiet ride and wear.

I just bumped the air pressure from 32 all around to 38 just to see if that improved things. It helped significantly. I think I'll bump it down to 36.

I'm really particular about this car and I notice every little nuance about this car. This recent tire incident drove me crazy.

Thanks again for a real response not just the usual banter.

[ErvGotti]

Originally Posted by old1

The RE760 is classified as an ultra high performance summer tire, so it should be good enough for the street, although admittedly not as stiff or sticky as the next level up max performance the car came with. When I switched to non-RFT's, I went with Michelin Pilot Sport A/S (can't justify the time/trouble/expense of winter tires down here, but wanted better cold weather performance--and ride) I noticed much less harshness and improved ride on our nasty city streets, but I also noticed much sloppier handling at high speeds out on the road. Made sense to me because having softer sidewalls is like switching to softer springs. So I upgraded to the BMW Perf. Suspension and it really did the trick. I'm running 37/39 PSI front/rear and really love the responsive cut and thrust of this setup.

Good point.

Alot of people dont know that BMW designed our suspensions softer to balance out the harshness of the RFT's. Switching to NonRFT's will cause it to feel I guess sloppier from the extra "Softness" you attain.

You might need to upgrade to a stiffer suspension to get that feeling back. I've upgraded to K sport coilovers and haven't looked back

[Red Bread]

Tire pressure makes a huge difference with "real" tires, not so much with the ridiculous run flats, which have pretty solid sidewalls. Sounds like you're well on your way to fixing this.

[Dackelone]

Originally Posted by Red Bread

Tire pressure makes a huge difference with "real" tires...

Tire pressures make a HUGE difference with run flats too.

[Red Bread]

Originally Posted by Dackelone

Tire pressures make a HUGE difference with run flats too.

But it doesn't effect feel as much. Sure, it effects tire wear and longevity of the run flats, but the feel isn't nearly as effected as it is with regular tires. This is one reason that folks have driven on flat run flats without knowing it, and why the TPMS is standard in the US.

[My135]

The RFT has a much stiffer side wall as compare to regular tire. I think this caused the difference in feel.

[SiN55]

It's to late, but that's your mistake unfortunatly. Car is designed for a sports tires like Potenzas, Michelin PS3 or similar but definitely not for tires with soft sidewalls. So, like someone said before, now you must do something with suspension. Good set of right springs or better, coilovers, and car is back in the game.

[nordique14]

Bridgestone tires can be hit and miss. I loved my RE-01 tires (on my BMW) while I hated the RE960AS (on my Subaru). And I did not hate them just because they were all season tires. They felt squirmy and did not track well on the highway. I always had the feeling of being on a slick road. I switched to a Continental tires and the car felt great again. I think the 760 may be another Bridgestone dud.

[Gary@TireRack]

Originally Posted by britt_e82

My car is an 08. Sluggish is probably not the best word. Still has plenty of power. It just isn't as stiff, and I really got used to the old feel. I've never really noticed any significant rolling when cornering and sloppiness on the highway until now. It reminds me of a 328 I got as a loaner when my car was in for its 30,000 mile service a few weeks ago. I probably just got used to the stiffer sidewall.

What should the tire pressure be on my setup? Could that be an issue? I haven't physically checked it but the paper work from the tire company states 32lbs. and door sill sticker states 36lbs.

There's a bit of misinformation regarding your tires, as I read through this thread.

The Bridgestone Potenza RE760 is a fantastic Ultra-High Performance Summer tire. I've had years of experience using them personally and they have delivered exactly what Bridgestone intended with this tire. They have excellent adhesion based on their performance category and they are longer lasting than most in the same group. After 1 million+ miles they are still our customers pick for #1 in the category.
They won't compare in grip to the Extreme Performance tires and they won't compare in wear and comfort to the Standard Touring tires (used on "Buicks") but they are wonderful for the driver who wants a great blend of performance characteristics and doesn't want to buy new tires every 10k miles.

It sounds like your concerns are coming from two sources. You were used to the ultra stiff sidewalls of the runflat tires and the pressure may have been set too low (should be 36psi f/r.)

Hopefully after you have a chance to make the pressure adjustment and drive on them for a hundred miles or so, you'll find them as satisfying as myself and the myriad of customers who rank this tire #1 in it's class.

[FJUNO78]

I'm all for ditching runflats, but I don't know if I would do that on my wifes car.

[bluesunit]

Roger the BMW suspension being tuned for the super stiff sidewalls on the RFTs. You are going to get a softer ride from that.

Also, new tires will be "squirmy" due to the increased tread depth . . . you'll get used to it.

Don't listen to people knocking your tire choice. If the aren't sporty enough, get something stickier the next time around. Cost of the tire rarely has anything to do with the performance of the tire . . . you are paying for the brand name. There are a ton of dirt cheap Yokohammas, Hankooks, and Kumhos that blow twice as expensive tires out of the water.

[bluesunit]

"That is not true after 5K, 10K, 15K or 20K where a better tire construction will not have noise, wear, or cupping problems on a perfectly aligned suspension with frequent rotations. In tires, you pretty much receive for what you pay."

I rarely get more than 15k out of a set of tires. By the time 10-15k rolls around on a performance tire, they've been heat cycled to death.

"There is a reason these brands do not compete in top level racing and do not come standard on top performing cars like Ferrari, Porsche, Lamborghini, or even BMW."

You don't think that has anything to do with race sponsorships and paying the manufacturers to use their tires? Maybe you should check out how Kumho, Toyo, and Yokohama do in SCCA racing . . .

"99% of the people recommending these tires have never owned the top tire from one of the Tier One manufacturers, but are bottom feeders."


Man, its nice . . . thanks for telling us what you really feel.

[britt_e82]

Thank you all for your reply's. especially the serious ones. It's awesome to read constructive comments from people who know and love our little 1's

Update:

I found out that I have 30 days to return these tires and apply what I spent on something else. (Nice perk)

I've been toying with different tire pressures. Currently running 40 all around. The tire shop had 29/32 front/back. I have know idea why they did that. The car is night and day different running 40 all around.

I want longevity for my tires. I have a bone stock car and actually had no problems with the RTF's other than price to replace. (I got 33,000 miles out of them and actually sold back the fronts with at least 5-8,000 more miles on them) I wanted to replace them with another set of Bridgestones and read some good reviews on the 760's.

Not sure If I'll keep them but I have 3 weeks to make up my mind. I'll put the car through it's paces the next few days and figure something out.

Thanks again for all the insight

[135forthewin]

Originally Posted by bluesunit

Also, new tires will be "squirmy" due to the increased tread depth . . . you'll get used to it.

+1. When I switched out my runcraps to Dunlop Direzza Z1 Star Specs, they did feel a little sloppy in comparison.

Keep in mind not only do you have full tread depth causing that squirmy feel, but you also no longer have sidewalls meant to support a nearly 3500lb vehicle (loaded weight) for at least 50 miles at 50 mph.

Sure, they might feel softer. Once you get your pressures right (I suggest somewhere around 33F 35R cold), toss her into a corner in a safe place. Make sure those bolsters of yours are tight because she'll grip like a mofo.

I would never suggest running 40 PSI cold. All this will do is where the center of your tire and cause an unstable feeling on breezy days at high speed. With a 40 PSI cold pressure, think of you tire as balancing on the middle part of the tread ONLY.

As for tread life, you'll have to deal with it. These cars have negative camber naturally (especially in the rear) and so the inside of the tires will wear more quickly. You have a 1er, and you like driving her, so my only suggestion to even out the wear is to hit an autox or road course every couple of months .

[escobar929]

i for one, cant wait to ditch them