[rickyjones1209]

I know it's recommended to increase tyre pressures for extended high speed runs. I'm heading Germany over the weekend and there will no doubt be some derestricted autobahn stints, what should I be setting the PSI to on the standard BMW 19 inch wheels?

[Turbonut]

I set mine to the maximum pressure as set on the B-Pillar - I was carrying equipment in the back so the car was reasonably heavy. Unfortunately the Autobahns were very busy so occasional blats to 120 or so was all I could do whilst staying safe. Very impressive how stable the car felt at high speed. Watch out for foreign registered cars pulling out in front of you...

[mikeoz]

HI
As above i go with the B pillar settings.
while you will be going fast, i doubt you will get hour after hour at over 120mph etc as the traffic wont allow normally...unless at night and the bahns are pretty dark at night and take a bit of getting use to at high speeds.

[Tengocity]

Is that right?

I've heard that you should increase the pressure for increased loads, but not for high speed running.

[rickyjones1209]

Apparently so. Something to do with the number of revolutions the tyres are doing at speed so the shape of the tyre changes, therefore higher pressure keeps more of the rubber on the road.

I think that's right lol!

[teaston]

I wouldn’t think there’s any need to increase pressures, at high speed the tyres will heat up and the pressures will increase.

[HighlandPete]

Yes, it is appropriate to increase pressure for higher speeds. Many tyre pressure placards, years back, gave pressure recommendations for normal and high speed use.

It is not only higher loads which require higher pressure, in fact at the top end of a tyre's load/speed rating, load capacity decreases as speed increases.

Here's a good explanation, plus some charts giving examples.

https://www.tyreleader.co.uk/tyres-a...ssure-to-speed

[....,,,,..,,..]

Originally Posted by Turbonut

I set mine to the maximum pressure as set on the B-Pillar - I was carrying equipment in the back so the car was reasonably heavy. Unfortunately the Autobahns were very busy so occasional blats to 120 or so was all I could do whilst staying safe. Very impressive how stable the car felt at high speed. Watch out for foreign registered cars pulling out in front of you...

Bloody foreigners, we obviously need more Brits over there and not those bloody locals

[Junebug85]

Originally Posted by rickyjones1209

I know it's recommended to increase tyre pressures for extended high speed runs. I'm heading Germany over the weekend and there will no doubt be some derestricted autobahn stints, what should I be setting the PSI to on the standard BMW 19 inch wheels?

I took my car to Munich in June. Standard 19" wheels/tyres. I just set my pressures to whats recommended for a fully loaded car. Hit 158mph (indicated on the HUD). everything was fine.

Enjoy your trip!

[ukbeemerboy]

I took mine to Munich in Feb this year, I just ran them at the normal pressures I do here. On the unrestricted Autobahns, you’ll only be doing fast stings in short bursts. The rest of the time you’ll be doing speeds that you’d do here. I shouldn’t over complicate things as you’ll have to remember to reduce the pressures too....

[gds54]

I took my previous car beyond its supposed 155 limiter without changing the tyre pressures, no ill effect.

[Wills2]

The pressure charts show you what cold pressure you should put the tyres to those figures are valid and have been tested up to the Vmax of the car.

I wouldn't go messing around picking a number out of thin air....

[Tengocity]

Originally Posted by ukbeemerboy

I took mine to Munich in Feb this year, I just ran them at the normal pressures I do here. On the unrestricted Autobahns, you’ll only be doing fast stings in short bursts. The rest of the time you’ll be doing speeds that you’d do here. I shouldn’t over complicate things as you’ll have to remember to reduce the pressures too....

This is what I was thinking really. No one sits doing 155 over there, more like a 90-120 is typical in say a 335d with normal to quiet traffic density.

[HighlandPete]

Originally Posted by gds54

I took my previous car beyond its supposed 155 limiter without changing the tyre pressures, no ill effect.

I'd hope not.... the problem in saying "no ill effect", you don't know if you were close to compromising the tyres or not.

What we do know, most tyre failures not due to penetration from objects as we drive, (delamination, blowouts, fatigue) are due to running low pressure. Triggered by overload, (excess heat), not setting for the weight carried and/or speed.

Saying that, most BMW models run pressures close to the pressure required for the maximum load rating (L.I.).

Many of us run pressures between the normal and full load pressure recommendation anyway, so not so critical for adding pressure.

Any doubt, run the higher recommended figure, for sustained high speed.

[Alscoob]

Originally Posted by Turbonut

Watch out for foreign registered cars pulling out in front of you...

That'll be the Belgies then.....

[djcowlin]

Dutch in my experience.

[rickyjones1209]

Just to update, made it to Koblenz and back with no issues. Tyre pressures were set cold to 40 psi for the whole trip so I'm guessing that would be about right.

Had a good run through Germany, good progress made on the Autobahns with several stints at the 155mph limiter. Hit the limiter with relative ease with the GPS app reading 154mph.

Did 4 laps on the Nurburgring too. As capable the 435d is, we all know that it isn't built for the track, but it performed very well considering. It's on the Eibach springs which no doubt helped matters. I was careful not to cook the brakes but I'm certain I was comfortably under 10 mins. A friend of mine followed in his track car with GoPro set up on his cage, so will share the video if anyone is interested.

Lots of M3s and M4s around tempting the upgrade lol!

[rickyjones1209]

Pic