Tyre Pressures for non-Run flats
- Thread starter Tommo
- Start date
hotdog3147
Member
Yes, they'll be the same mate.
It's an interesting question. When I changed the rfts on my 120 from Euforias to Sportcontact2s I found that I had to add 0.2bar to get the same handling characteristics (without the tramlining and with some wet weather grip, that is).
Having changed the Z4 to F1 Asymmetrics I found that the steering felt heavier, although more precise, so I tried doing the same with the pressures. Far too hard, the standard pressures felt better.
I don't know but perhaps it depends on the tyre you've replaced them with. Goodyear GSD3s for example, have, I'm told, a softer side wall (as did my Sportcontact2s I suspect) which will affect what pressure feels right.
I'd be inclined to start with the standard pressures and see how it feels. If you deviate too far from standard settings and are unfortunate enough to have a bad prang then it will be checked and may be taken into consideration when considering liability. Don't forget to make sure your insurance co knows you're running 'non-standard' tyres too.
Having changed the Z4 to F1 Asymmetrics I found that the steering felt heavier, although more precise, so I tried doing the same with the pressures. Far too hard, the standard pressures felt better.
I don't know but perhaps it depends on the tyre you've replaced them with. Goodyear GSD3s for example, have, I'm told, a softer side wall (as did my Sportcontact2s I suspect) which will affect what pressure feels right.
I'd be inclined to start with the standard pressures and see how it feels. If you deviate too far from standard settings and are unfortunate enough to have a bad prang then it will be checked and may be taken into consideration when considering liability. Don't forget to make sure your insurance co knows you're running 'non-standard' tyres too.
This is a great question. I set my non-rft Conti's to the pressures listed in the door jamb and it felt way too harsh. I'm running 32/35 now, and it's much better, but still not 100% happy. Might try 32/32 though to see if it helps settle the rear end down a bit. With a 50/50 weight distribution it would seem like the same pressure on all 4 corners would make sense, with maybe 1 or 2psi in the front or rears to alter the cars feel to your preference.
Not as straight forward as I thought. I went for 33 all around in the end.
My pressures were all over the place!
Front - 35 - 33
Rear - 24 - 45
The car feels so much better over bumps in the road now. Feel stupid for not checking this sooner!
Can someone confirm what tyre sizes my car should have, its got the 108 5 spoke alloys (18inch).
My pressures were all over the place!
Front - 35 - 33
Rear - 24 - 45
The car feels so much better over bumps in the road now. Feel stupid for not checking this sooner!
Can someone confirm what tyre sizes my car should have, its got the 108 5 spoke alloys (18inch).
Maybe I'm an idiot (most probable) - I think the German's provide this information?Tommo said:Not as straight forward as I thought. I went for 33 all around in the end.
My pressures were all over the place!
Front - 35 - 33
Rear - 24 - 45
The car feels so much better over bumps in the road now. Feel stupid for not checking this sooner!
Can someone confirm what tyre sizes my car should have, its got the 108 5 spoke alloys (18inch).
I'm running non RFT Falken 452's and all was fine unitil I had the rears repalced and had all 4 filled (for free) with Nitrogen, this has a considerable affect on the front end stability (tramlining) at motorway speeds, the fronts are inflated to 32psi as before.
I have a feeling that that as they are not affected as much by the heat rise of normal air (up 4-5psi after warming up) they are running under inflated at motorway speeds causing the stability issue
I have a feeling that that as they are not affected as much by the heat rise of normal air (up 4-5psi after warming up) they are running under inflated at motorway speeds causing the stability issue
Can I pick up on an old thread?
Was this ever decided on?
I've got a 2009 e89 sDrive35i and have just replaced my runflats with non runflat Goodyear F1 Asymmetric 2's I tried the same pressure as the Runflats but it felt awful, hard and v twitchy at speed, so have just lowered all round.
Any other follow up experience?
I think before I was running at
38psi front
45psi rear
Which does seem silly high.
Now on 32 front 38 rear
Any tips?
Cheers
David
Was this ever decided on?
I've got a 2009 e89 sDrive35i and have just replaced my runflats with non runflat Goodyear F1 Asymmetric 2's I tried the same pressure as the Runflats but it felt awful, hard and v twitchy at speed, so have just lowered all round.
Any other follow up experience?
I think before I was running at
38psi front
45psi rear
Which does seem silly high.
Now on 32 front 38 rear
Any tips?
Cheers
David
For info, Alpinas all run non-run-flat as RFT's are the spawn of the devil :evil: . Therefore I have the pressures for 18" and 19" non-rft's on the door-jamb.
On 18" wheels the recommended pressure is 2.3 bar (33psi) front, 2.6 bar (38psi) rear. For 19" it's 2.2 bar and 2.4 bar respectively....which is what we run. I would imagine that these would be similar for non-Alpina models as the weight distribution is very similar...whatever, it's a good start point.
As a point of note, driven wheels usually have a higher running pressure than the non-driven wheels.
On 18" wheels the recommended pressure is 2.3 bar (33psi) front, 2.6 bar (38psi) rear. For 19" it's 2.2 bar and 2.4 bar respectively....which is what we run. I would imagine that these would be similar for non-Alpina models as the weight distribution is very similar...whatever, it's a good start point.
As a point of note, driven wheels usually have a higher running pressure than the non-driven wheels.