Tyre Question

[Hugo_za]

Hi guys,

My 7er needs new shoes, and I was wondering about the sizes. Currently she runs on 245/45/19 front and 275/40/19 rear.

Question is, what impact would going with 245/40/19 on the front have?

 

[tivoli786]

Harder ride for one

 

[Gunner-Win]

That will decrease the height of the side wall. So it will mean the car will sit slightly lower, ride will be slightly harder, and the rim will be more likely to get damaged due to there being less tyre between the road and rim.

At the same time the rolling circumference of the tyre will change. The rolling circumference will decrease very slightly resulting in more acceleration and less top speed. Although the difference will be very slight.

It will also mean your speedometer reading will change. So if before the change your speedo said 120 and your gps said 115, it might change to speedo speed of 120 and gps to 114/116 for example.

Edit to add: Use this website for any tyre change information you need:

http://www.willtheyfit.com/

 

[moranor@axis]

you looking at a diameter difference of around 25mm I wound not do it wheel arch will look empty ride will get worse and your car may also get errors because the wheel senors will pickup that the fronts are spinning faster...

 

[sash]

That will decrease the height of the side wall. So it will mean the car will sit slightly lower, ride will be slightly harder, and the rim will be more likely to get damaged due to there being less tyre between the road and rim.

At the same time the rolling circumference of the tyre will change. The rolling circumference will decrease very slightly resulting in more acceleration and less top speed. Although the difference will be very slight.

It will also mean your speedometer reading will change. So if before the change your speedo said 105 and your gps said 100, it might change to speedo speed of 105 and gps to96 for example.

Edit to add: Use this website for any tyre change information you need:

http://www.willtheyfit.com/

its a 3.4% difference... too much for my liking, unless going bigger in the rear.

Just realised the the change is in the front.., dont think it will affect the speedo or gps speed, definitely the look as mentioned my Moranor

 

[Hugo_za]

I've gotten quotes from BMW for OEM and have also asked Ralf to quote as well.

 

[Ralf*]

I've gotten quotes from BMW for OEM and have also asked Ralf to quote as well.

will that be RFT or STANDARD ?

I am on "good terms" still with Pirelli, Yokohama/Achilles and with SATyre distributors (Maxtrek/Pace/Windforce/limited Goodyear/limited Bridgestone suppliers)

?

 

[Hugo_za]

I've gotten quotes from BMW for OEM and have also asked Ralf to quote as well.

will that be RFT or STANDARD ?

I am on "good terms" still with Pirelli, Yokohama/Achilles and with SATyre distributors (Maxtrek/Pace/Windforce/limited Goodyear/limited Bridgestone suppliers)

?

Non runflats. Need something with a decent price/performance ratio

 

[Ralf*]

I've gotten quotes from BMW for OEM and have also asked Ralf to quote as well.

will that be RFT or STANDARD ?

I am on "good terms" still with Pirelli, Yokohama/Achilles and with SATyre distributors (Maxtrek/Pace/Windforce/limited Goodyear/limited Bridgestone suppliers)

?

Non runflats. Need something with a decent price/performance ratio

Wow...spent almost an hour on the phone to various suppliers, and this is a difficult size to get hold off, most manufactures do RFT in 19''

sent you a PM !

 

[Gunner-Win]

I've gotten quotes from BMW for OEM and have also asked Ralf to quote as well.

will that be RFT or STANDARD ?

I am on "good terms" still with Pirelli, Yokohama/Achilles and with SATyre distributors (Maxtrek/Pace/Windforce/limited Goodyear/limited Bridgestone suppliers)

?

Non runflats. Need something with a decent price/performance ratio

Wow...spent almost an hour on the phone to various suppliers, and this is a difficult size to get hold off, most manufactures do RFT in 19''

sent you a PM !

Yeah it's an unusual size, but I do know of one tyre that will work, the Bridgestone Potenza S001.

 

[Ralf*]

Yeah it's an unusual size, but I do know of one tyre that will work, the Bridgestone Potenza S001.

I was succesfull on Pirelli "Rosso's"

 

[ChefDJ]

Keep the standard sizes for ride quality, Hugo. You don't want to compromise when it comes to a 7 series.

 

[Got-Turbo]

Keep the standard sizes for ride quality, Hugo. You don't want to compromise when it comes to a 7 series.

+1

 

[Gunner-Win]

Yeah it's an unusual size, but I do know of one tyre that will work, the Bridgestone Potenza S001.

I was succesfull on Pirelli "Rosso's"

Oh cool, those are also very nice tyres. :coolShake:

 

[Hugo_za]

Thanks for the comments folks. Its not that I want to change the size, but more a case of availability of the oem sizes.

 

[Hugo_za]

OK decided to go with Michelin Pilot Sport. Got a great deal on them, and going only a smidgen wider. 255/45/19 and 285/40/19. This works out to a -1.13% speed difference which I am happy with, and only 4mm increased ride height.

 

[Bugger]

Those are fine tyres, but they wear VERY quickly. The set on the back of my M6 lasted all of 15,000kms. And BMW don't actually charge that much for the tyres, comparatively speaking.

 

[Hugo_za]

Had them fitted this morning an my initial impression is WOW. Virtually silent, grips like a mofo around corners. Money well spent.

 

[that_guy_Ettiene]

Michelin's FTW!!