Run Flat Tires?

You might try Tire Rack and get their input and opinion on run flat tires.

 

IMHO, worst tires you can buy. Just took a set off my 2013 Cali.

 

Why, Don? My Cadillac STS-V came with Pirelli run-flats. They handle and grip very well indeed, perform well in the wet and I've had the car with them on track at Watkins Glen, tho' really only for 'parade' laps. But they've been fine and the ease of mind is worth the trade off.

I wouldn't put a set on my 575M but I wouldn't hesitate to put them on my 412.

 

Weight is the biggest problem. Run flat tire have to have a lot more reinforcement than its traditional counterpart. One of the worst areas of a car to have extra weight, you have the unsprung weight which affects the suspension, and the rotational mass which affects the acceleration and braking.

When new cars come with them they are designed for the added weight, it's a bad idea IMO to add them to a car that wasn't born with them.

If you think your new car handles well with RFTs, switch to a traditional performance tire, it makes a world of difference.

 

Run flats were the hot new thing a few years ago, but I have seen them used less and less because of the poorer handling and ride quality. Nowadays it seems like the tire pressure monitoring systems have proven to be more popular.

 

Until you get a flat, I don’t have a spare tyre, run flats sounds great....

 

My car, 08 spider, came with them from factory. Goodyear f1. They are discontinued. I had them on all four wheels. I had to replace the front and got Pirelli. Back still has run flats. Will replace them soon. Ferrari doesn't suggest using run flats anymore. They are too hard....

 

Correct; my STS-V was factory-equipped with the Pirelli run-flats and as beautifully engineered as the car is, one should assume that it was designed with run-flats in mind. As spourezza comments, they do run quite hard. With no spare in the trunk, it feels a good deal more secure.

 

I had a Mini Cooper S that came with run flats. A lot of owners replaced them with regular tires and put a spare in a bag (available on the internet) behind the passenger seat. Much better handling.
Alan

 

There is no question that lowering unspring weight improves a car's handling. I've been trying to discover just how much weight is added to each rim by use of a run-flat. Can't find.

But as a practical matter, in everyday driving I doubt very much that any of us, myself included - and I've raced sports cars in the US and in Europe - would notice the difference unless we were tracking our cars with those lighter rims ;-)

'Much better handling'? With great respect, I doubt it.

 

I respectfully disagree. Your right about them making a bigger difference in a race type environment, everything on a track is amplified because your driving so much harder, however, I have immeidiatly noticed a difference in cars that I've changed from RFT's to traditional tires.