The Theory of "Run Flat" Technology.....

[Footy]

<blockquote class=`ipsBlockquote` >

<em class=`bbc`>Originally posted by Brad B. [/i]
<strong class=`bbc`>By the way, I bet nobody knows what the red square with the round hole is on the side wall. I think we need a contest. C`mon folks, take a guess! [/b]</blockquote>It`s obviously a medieval device for detailing (as in De-Tailing) cats

[rstype]

I thought you detailed under a mongoose fur covered garage! :D

[imported_Luster]

Here`s how it is supposed to work:

Run Flat Tires or Run Flat Technology (RFT) is a concept that eliminates the need for a spare tire and a jack. The extra thick and extra stiff sidewalls provide enough support to remain vertical even with no air pressure.

Goodyear calls their run flats Extended Mobility Tire (EMT). Michelin calls theirs Zero Pressure (ZP). Kuhmo simply uses RFT.

The theory being that you can still drive on the tire even though it doesn`t have any air pressure.

One of the major reasons for using run flats is to save weight. When Chevrolet went to run flats in the C5, they saved 80 pounds by eliminating the spare tire and the jack.

There are plusses and minuses and arguments in both directions.

Positives:

1. Weight savings
2. You can drive on a "flat" tire for "x" miles without damaging the tire.


Negatives:

1. They`re noisy
2. They are expensive
3. They are "hard"
4. They require Tire Pressure Sensors (otherwise you don`t know if you have a flat!)
5. They have a short lifespan (20k-25k typical)

As you can probably read into this thread, I`m not a fan....

What are your thoughts on Run Flats?

[bmw5541]

Bill,

I have them on my BMW and I absolutely HATE them. Everytime I hit even the smallest bump in the road, it feels as though the bottom of my car will fall out. They are so stiff!

I have already blown out two tires and ruined three rims because of the tires. They do run for quite a long period after you blow them out.

If anybody is considering a car with these tires, make sure to buy the tire insurance. It will pay for itself immediately, because you will likely go through a set or two.:cursing::cursing::cursing::banghead::banghead ::banghead::mad::mad:

[imported_Luster]

Bill,

I have them on my BMW and I absolutely HATE them. Everytime I hit even the smallest bump in the road, it feels as though the bottom of my car will fall out. They are so stiff!

I have already blown out two tires and ruined three rims because of the tires. They do run for quite a long period after you blow them out.

If anybody is considering a car with these tires, make sure to buy the tire insurance. It will pay for itself immediately, because you will likely go through a set or two.:cursing::cursing::cursing::banghead::banghead ::banghead::mad::mad:

I feel your pain.

When people ask me how smooth the ride is with RFT`s on the Vette I simply tell them:

"Well, if I run over a dime I can tell you whether it`s heads or tails.!"

[dennn]

What are your thoughts on Run Flats?

While they are not the best tires in the world, you will love them whenever you hit a nail or something!!!

Yes, they are expensive. Yes, they are stiff. But to some that`s a small price to pay. They are also bad on fuel economy in fact because they are quite heavy. They add an average of roughly 20lbs of spun mass, which hurts handling, braking, and acceleration. It is better to add a 40lbs spare tire to the trunk than 20lbs at the wheels.

My car was equipped with Bridgestone RFT`s, but I swapped them out to for some hyper-performance Continental tires. The ride comfort, fuel economy, handling, braking, and acceleration improved drastically!

[imported_Luster]

While they are not the best tires in the world, you will love them whenever you hit a nail or something!!!

Yes, they are expensive. Yes, they are stiff. But to some that`s a small price to pay. They are also bad on fuel economy in fact because they are quite heavy. They add an average of roughly 20lbs of spun mass, which hurts handling, braking, and acceleration. It is better to add a 40lbs spare tire to the trunk than 20lbs at the wheels.

My car was equipped with Bridgestone RFT`s, but I swapped them out to for some hyper-performance Continental tires. The ride comfort, fuel economy, handling, braking, and acceleration improved drastically!

I`m strongly considering buying non-run-flat tires for the `03 Corvette. They`re less than half the price and all the issues you listed above go away.

In all my cars I carry a tire plug kit, folding 4-way wrench, scissor jack, 12v mini air compressor... Why couldn`t I do the same with the Vette?

Sure would save me a lot of aggrevation!:banghead:

[bmw5541]

:banghead:I tell ya Bill, if I had the extra money lying around, I would get rid of my Run Flats in a heart beat!
Did I mention how much I HATE them:cursing: