today on my way to work my i drive informed me that i had a flat. Upon stopping the car and getting out to investigates i could not see any flat tyres

Dealer subsequently inspected the tyres and could not find any problems. They just reset the i drive.

Anybody else had this problem. Is it easy to tell if run flats are punctured or do you have to check air
pressure

 

Its been a on and off problem since day 1. BMW used a cheap technology which compairs revolutions of each wheel to the others. If one is higher it sets off the alarm. It is very hard to tell if a run flat is flat

 

Which is why you shouldn't ignore the warnings. You never know for sure until you verify the pressures.

Personally, I've never had a false warning. My previous set of tires had a slow leak that would cause a warning every few days -- but it was telling the truth every time...

 

I would say a low cost implementation of tire monitor, not cheap. Most OEMs use the cheapest solution for certain items, which is a good thing if the price is right.

 

GM uses pressure sensors in most of their cars. I consider some of their cars kinda cheap.

 

ACURA RL shows a schematic with tire pressure for each wheel in PSI or BAR

 

Now thats more like it!