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View Full Version : Tire pressure for Continental SSR RFT 245/45/18 RFT and ride comfort


baloo588
01-14-2011, 03:08 PM
I find 35/38 too high for my Continetal SSR runflats and it transmit road irregularities in the rear on highways 70 mph and above. The tires are all fine and road forced balanced very well below 8 lbs but I just do not like the ride comfort with these tires on my new 535 xdrive because of the stiffer side wall and cold temperatures that lead to bumpy ride on highways. The car is smooth around city and over small bumps. What pressure would be better? 32/33 psi for Front/Rear ?

I want to change them out to non-rft tires such as the Michelin Primacy MXV4 which I had on my Lexus GS300 awd and they were excellent ride comfort with good handling.

Anyone switch out the RFT on their 18 inch rims for better non-runflats who can enlighten me with their feedback on the non-RFT on the highways.

markl53
01-14-2011, 05:49 PM
I have the standard Goodyear LS2's on my 535i. 35/38 is for >100 mph or with full load in my manual. I set them to the 33/36 as indicated for normal load <100 mph. I think the ride I'm getting with these tires is excellent.

dunderhi
01-14-2011, 07:55 PM
Anyone switch out the RFT on their 18 inch rims for better non-runflats who can enlighten me with their feedback on the non-RFT on the highways.

I did on my 335d and it made huge improvement in ride quality and road feel. The 5 has softer setup in general, so the difference may not be as big. Unfortunately, I won't be able to share my first hand experience with the 5 until this summer.

highyo
01-14-2011, 08:30 PM
to be clear, what is the normal recommended setting? do you believe this is too high? and does that mean it is ok to go to a lower number?

markl53
01-14-2011, 09:10 PM
to be clear, what is the normal recommended setting? do you believe this is too high? and does that mean it is ok to go to a lower number?

There are many different tire combinations depending on options. There are several pages of specific tire inflation information in the owners manual. There are charts for <100 mph, >100 mph and fully loaded conditions. The placard on my 535i door shows the maximum pressures for my tires, that is not how I set them by following the more detailed info in the manual.

baloo588
01-15-2011, 09:04 AM
Thanks markl53.

Does anyone have the Continental Contiprocontact SSR RFT all seasons on their xdrive models? I decreased the pressure to 35/33 F/R to make it better. I will drive it more on the highway to see how it feels.

FastMarkA
01-15-2011, 09:18 AM
For those w/ non-RFT, what happens if you get a flat since we have no spare?

And on that note, I just realized the storage space in the trunk my F10 will be about the same size as that in my E60. I wonder what they did with the donut space that's in my E60?

dunderhi
01-15-2011, 10:04 AM
For those w/ non-RFT, what happens if you get a flat since we have no spare?

And on that note, I just realized the storage space in the trunk my F10 will be about the same size as that in my E60. I wonder what they did with the donut space that's in my E60?

I have the BMW Mobility Kit (as supplied with new M cars which don't have RTFs or spares), 24/7 Roadside Assistance, BMW Assist, and of course friends and family.

baloo588
01-16-2011, 12:59 PM
Decreasing tire pressure to 34/33 F/R helped quite a bit and made the ride more forgiving. I will drive it more to break in the car and tire. The car only has 490 miles on it and I had a rear left tire replaced few days ago because of a defective tire that came on car from factory.

baloo588
01-18-2011, 12:46 PM
So far at 700 miles, I still feel that the Continental Contiprocontacts SSR rft transmit road irregularities on the highway from the rear of the car but not in the steering wheel or from front of car. It feels like a small vibration in the back of my seat but its really the road imperfections since I drove a similar 535 xdrive with continental rfts and felt the road feedback, ripples, etc at 70-80 mph on the highways too. You can see in both my car and in a demo car that the passenger seat shakes a little bit on the highway signifying that the tires are made of stiff compound and the cold weather can have an effect (35 degrees outside). I am surprise that BMW puts these same RFT as they do on the 3 series sedans and coupes. My 4 tires are balanced well and have road force numbers of 2. 3, 6, and 8 lbs. The tire pressures were varied from 33 cold to 36 cold in the rear with little difference.
I am not sure how the Goodyear eagles Ls rfts compare to the continentals under same road conditions.... If this is a character of RFTs especially on a new 5 series with a softer suspension, then I will have to get them off the car and get decent grand touring all season Michelins. Anyone have same feelings or comments?