[craigbeal]

Looking at tyre options and seems a lot more in the 245/35/19 over my current standard sized setup.

Basically does this setup work ok as from what I've read it only give about 1% different in speedo reading etc.

[alohasurftoad]

here are some pics(not my car) of 442M, where the fronts are swapped from 225/40/19 to 245/35/19. although you may lose a little bit of initial turn-in sharpness of a 225, the overall handling improvement from reduced understeer will be worth it.

i believe the speedo gets it signal from the left rear axle so there will be no affect on your speedo/odometer.

[blschaefer1]

I went from 225/40/19 rft’s to 245/35/19 Michelin Sports 4S in the front (stock 255 width in the rear). Great upgrade, understeer much reduced, grip much improved. Might have suffered a slight loss in turn in sharpness, tough to tell.

[ctbear]

Originally Posted by blschaefer1

I went from 225/40/19 rft’s to 245/35/19 Michelin Sports 4S in the front (stock 255 width in the rear). Great upgrade, understeer much reduced, grip much improved. Might have suffered a slight loss in turn in sharpness, tough to tell.

How much did comfort improve when you went from rfts to the regular tires on the stock 19" rims? Are you still afraid of pot holes and ruts in the road?

[Jvac]

Originally Posted by ctbear

How much did comfort improve when you went from rfts to the regular tires on the stock 19" rims? Are you still afraid of pot holes and ruts in the road?

Vastly improved for me. I just switched from the stock 19" run flat to a set of Firestone indy 500 summer tires and the car is so much more comfortable and quiet at speed. Got a screw in the shoulder of one front wheel and since the rears were pretty worn I ditched them all.
I kept the 19" staggered setup of 225/40 front and 255/35 rear because these guys know more about tires than I do, but I know enough to say definitively that the run flats are the worst thing about these cars and you will not be missing them if you decide to switch. Roads are quite bumpy here in Dallas and the difference for me in daily driving is dramatic.

[track.n.trail]

I switched to the Firestone Indy 500s as well in the stock 225/255 sizes and also saw a dramatic improvement in comfort and reduction in road noise.

[ctbear]

Originally Posted by Jvac

Vastly improved for me. I just switched from the stock 19" run flat to a set of Firestone indy 500 summer tires and the car is so much more comfortable and quiet at speed. Got a screw in the shoulder of one front wheel and since the rears were pretty worn I ditched them all.
I kept the 19" staggered setup of 225/40 front and 255/35 rear because these guys know more about tires than I do, but I know enough to say definitively that the run flats are the worst thing about these cars and you will not be missing them if you decide to switch. Roads are quite bumpy here in Dallas and the difference for me in daily driving is dramatic.

Originally Posted by dotfiles

I switched to the Firestone Indy 500s as well in the stock 225/255 sizes and also saw a dramatic improvement in comfort and reduction in road noise.

Thanks for the feedback guys. The stock runflat S001 potenzas on 19" 225/255 ride like stagecoach wheels. I find myself dodging manhole covers...even the ones that are flush on the road that other people don't even notice. The slightest rut or crack on the road can be bone jarring....

What PSI are you guys running at? Did you get the XL rated tires (supposedly they support more weight and are stiffer to minimize loss of steering immediacy when changing from run flats)

[Jvac]

The xl models are the ones I have. Most of the non rft options have a higher load rating than the stock rft which are 89 I think, vs 93/96xl for the indy 500s. These particular tires are ONLY W rated instead of Y, so max speed 168 instead of 186. It Didnt matter to me because I doubt I'll ever have a chance to go that fast... But they are running a 60$ rebate on tire rack right now with purchase of 4. Hard to beat the price. I am running the stock pressure from the door placard until someone educates me otherwise or I start doing track days.

Originally Posted by ctbear

Thanks for the feedback guys. The stock runflat S001 potenzas on 19" 225/255 ride like stagecoach wheels. I find myself dodging manhole covers...even the ones that are flush on the road that other people don't even notice. The slightest rut or crack on the road can be bone jarring....

What PSI are you guys running at? Did you get the XL rated tires (supposedly they support more weight and are stiffer to minimize loss of steering immediacy when changing from run flats)

[ctbear]

Originally Posted by Jvac

The xl models are the ones I have. Most of the non rft options have a higher load rating than the stock rft which are 89 I think, vs 93/96xl for the indy 500s. These particular tires are ONLY W rated instead of Y, so max speed 168 instead of 186. It Didnt matter to me because I doubt I'll ever have a chance to go that fast... But they are running a 60$ rebate on tire rack right now with purchase of 4. Hard to beat the price. I am running the stock pressure from the door placard until someone educates me otherwise or I start doing track days.

There was some talk in other threads of people running higher PSI for faster steering and less "mushy" feeling

[MONSTAR]

Im on 245/40/19 front (19x8.5 +35) and 265/35/19 rear (19x9.5 +40) and its a dream. I only wish I could go bigger in the rear but I was advised against 275's.

[Jvac]

Originally Posted by ctbear

There was some talk in other threads of people running higher PSI for faster steering and less "mushy" feeling

Just found this on another site
https://axleaddict.com/auto-repair/Checking-Tire-Pressures-Aftermarket-Wheels
A spirited or aggressive driving style will generally warrant somewhat higher tire pressures than a sedate conservative style. Higher tire pressures will keep the tires from rolling-over and flexing so much when subject to lateral G-forces.

Somewhat related to driving style is the temperature of the tread. Rough driving heats up the tread. So does driving on pavement baked by 100° ambient temperatures (the paved surface is a lot hotter than that). Either way, heat beyond a certain point will weaken the rubber tire compound enough to dislodge small chunks under severe braking or cornering. Higher tire pressures will reduce heat build-up.

So the chaps who you mentioned are on to something, but how much is too much?
This site has a diy road test for determining the optimum tire pressure on your specific car/wheels. Looks like a pretty good way to dial in the pressure instead of using the placard on the door, which, in my case iwas made for a different type of tire (rft/non rft) with a different load rating.

[ctbear]

Originally Posted by MONSTAR

Im on 245/40/19 front (19x8.5 +35) and 265/35/19 rear (19x9.5 +40) and its a dream. I only wish I could go bigger in the rear but I was advised against 275's.

That's a lot of rubber. What do you like about that setup compared to stock?

[Dheeth-G80]

I am 245/275 and it's a lot of grip in a straight line and on turns, honestly didn't notice any turn in reduction or anything negative of that sort. Good luck tho

[MONSTAR]

Originally Posted by ctbear

That's a lot of rubber. What do you like about that setup compared to stock?

I love the grip that I have with this setup -- you'd probably like it with the extra power that you have in the 335i.

My only experience with this car before this set up was with the factory wheels and run flats that were very unpredictable. These tires now (my 2nd set already) are very predictable all the way up to loss of traction and very controllable