Tire pressure Run flat vs regular tires

[Old-Duckman]

Just got my Z titled so I can officially use it without worrying about getting pulled over.

So, I checked the tire pressure, door tag says: front - 33 PSI (2.3 bar) Rear - 36 PSI (2.5 bar). The front tire reads 27 PSI (1.9 bar) I didn't check the rears.

My question is did the previous owner have the tires seriously under inflated or do regular tires take less pressure than the run flats ?

My tire size is 225/40Z R18.

Thanks

 

[Singapore stag]

Just got my Z titled so I can officially use it without worrying about getting pulled over.

So, I checked the tire pressure, door tag says: front - 33 PSI (2.3 bar) Rear - 36 PSI (2.5 bar). The front tire reads 27 PSI (1.9 bar) I didn't check the rears.

My question is did the previous owner have the tires seriously under inflated or do regular tires take less pressure than the run flats ?

My tire size is 225/40Z R18.

Thanks

What Z have you got?
My sticker reads 2.00 bar front and 2.3 bar rear, I have 225 40 18's

Check this out.
https://www.tpressure.com/model/bmw/z4/cabrio.html

 

[Old-Duckman]

Just got my Z titled so I can officially use it without worrying about getting pulled over.

So, I checked the tire pressure, door tag says: front - 33 PSI (2.3 bar) Rear - 36 PSI (2.5 bar). The front tire reads 27 PSI (1.9 bar) I didn't check the rears.

My question is did the previous owner have the tires seriously under inflated or do regular tires take less pressure than the run flats ?

My tire size is 225/40Z R18.

Thanks

What Z have you got?
My sticker reads 2.00 bar front and 2.3 bar rear, I have 225 40 18's

Check this out.
https://www.tpressure.com/model/bmw/z4/cabrio.html

Thanks for the link, It is basically what the door tag says but with a high/low range.

My guess is that since I picked it up 500 miles south of where I live (it was in the 50's [F] there) and the temp here today is in the teens [F], that the pressure is low because of the cold weather...I'll air up before I drive the car tomorrow.

Thanks for the reply.

 

[Singapore stag]

 

[CHIMV8]

I’m still not sure on pressures

In the active world Griffs and Chims ran at 22-24F and 24-26 R

Ok fibreglass bodied but would have thought the z E85 is a lot heavier

 

[buzyg]

I’m still not sure on pressures

In the active world Griffs and Chims ran at 22-24F and 24-26 R

Ok fibreglass bodied but would have thought the z E85 is a lot heavier

There is a bit more to it than simply weight. I recall the tubs on my push bike, used to be over 100 psi. :wink:

 

[CHIMV8]

If we up the rubber do we still go with the body stamp pressure

 

[BTZ461]

If we up the rubber do we still go with the body stamp pressure

If we up the rubber do we still go with the body stamp pressure

We run 30psi front and rear in our Z4 coupes, and if carrying passenger and luggage and wanting to press on, go to 32psi on the rear. Wearing standard sizings and 18 inch tyres.

 

[Jembo]

It’s also worth checking your guage... I had 2 same make digital gauges... 1.5 psi difference ... found after comparing to a few friends gauges the one that was spot on... so don’t assume the reading u get is correct

IMO run flat/ normal is no different

I ran the recommended F33 & R36 on my old 3.0 & was perfect

My M’s recommended pressures are F30.5 & R32 & again seem good... did try F33 & R36 once & strangely was horrible... ho hummm