Donnymac

I drove 330 miles today on the IH. Psi bounced from 38-41.

Tomorrow I'm dropping to 33 on all corners. Tires are 20" Pirellis. Ride was harsh at hwy speeds although not the slickest road surface either.

thoughts?

1bad540

whatever it says on the door jamb,fuel filler door. Whicj i believe is 33-38

Donnymac

If dropping to 33 doesn't get close to my 2012 S550 ride, RF are headed to the dumpster.

1bad540

The runflats are terds. I dropped them 2nd week I had the car.

Donnymac

Are you on 19 or 20s and what tire did you go to?

i dropped to a cold 33 all around and did a quick 80 mph run. Psi jumped and hung at 37.

seamus2154

I have lowered the psi also with no luck. The runflats are that bad. Its a heavy car and the sidewall has to be able to support the car if flat....which equals a very stiff hard sidewall regardless of psi. When I slowly go to enter my garage there is a 1 1/2" elevation and when I hit it it bangs as if no give at all in the tire. Michelins to come!!

Donnymac

Are you on 20s?

My afternoon psi experiment was a bust. Tires gain 4psi running at 80. I'll reset to 32 in the AM when it's cool. Try again but not anticipating much from a RF.

seamus2154

Yes, I am on 20's. psi has always made a noticeable difference on some of my cars, some like a little more, some improve with a little less.........not these runflats. I have the Goodyears. Short sidewall, heavy car.

1bad540

Im on the conti dws 06 on 20" wheels.

Phillyfinest

I took off my 19inch OEMS with runcraps, and put 20inch aftermarkets with the same conti dws 06 and the ride is night and day. I did get the mini spare with short lugs like Streamliner did. Didn’t get jack and all as in the event i get a flat, i will be calling roadside to come change my spare.

1bad540

I did the same but I have the lug tools and jack. ps it fits inside the spare wheel. I would say you should have it.

flint350

My 2018 S560 shows different recommended psi pressures: driver's door 41, fuel cap shows 32. I don't know if it's a misprint/error or how to explain it. Dealer had initially inflated to the door pressure of 41. I have my first service A scheduled in 30 days and will ask then.

new550

flint350 - what did dealer tell you about door vs fuel flap sticker listing different psi? my 2015 has same conflict....

new550

flint350

I am taking it in next week for the A service and will ask then. For now, I run non-run flats at 40 psi.

Mitch Alsup

a) get rid of the run craps
b) set the tire pressure to 39 PSI all round.

(b) improves traction and tire life.