Correct speed rating for my tyres

[MSPORTBMW]

Hi guys....just need something clearing up.
Basically I'm about to change my run flats for normal tyres as I've heard the ride is better...plus they are less expensive.
I've got a 2009 3.0d msport. My tyre sizes are...255/50/19 on the front. And the rears are 285/45/19. At the moment the Bridgestones I have on are speed rated 107 front and 111 rear. Are they the correct speed ratings for the front and rear.
It's just that I've seen some mid range tyres for the rear (285/45/19) but they are rated at 107....could I fit these? Or would it have to be 111 rated?
Thanks

[Horizon]

[quote="MSPORTBMW"]
Hi guys....just need something clearing up.
Basically I'm about to change my run flats for normal tyres as I've heard the ride is better...plus they are less expensive.
I've got a 2009 3.0d msport. My tyre sizes are...255/50/19 on the front. And the rears are 285/45/19. At the moment the Bridgestones I have on are speed rated 107 front and 111 rear. Are they the correct speed ratings for the front and rear.
It's just that I've seen some mid range tyres for the rear (285/45/19) but they are rated at 107....could I fit these? Or would it have to be 111 rated?
Thanks
[/quote]
The numbers are the " Load rating " the letter V or W on the tyre is the speed rating. Have a look on the plate inside the door jarm  to see if the correct load and speed ratings are on the tyre pressure info plate. Or use the search button on the forum , swapping to Runflats on the E70 has quite a few previos threads, so you will get loads of info

[sid10]

Usually this is for the weighting of the tyre so the higher the load rating the more weight the tyre can take eg. Towing a trailer or using a roof box , bike racks or general heavy items .
To be honest this is more important than most other things to look out for as if involved in an accident they will check your tyres are the ones specified by the insurance as well as the depth .
  It is hardly worth going for a lower weight rating to save a few quid and altering the way the car performs or for your own safety , I would stick to manufacturers recommended tyres although a lot of people stick budget ones on and are very happy .

[X5Sport]

You must not go below the manufacturers rating.  You can go above it though.  The correct minimum load index rating required by the manufacturer should be on the tyre pressure plate on the B-pillar.