steel belted radial tires. What are they?

You kidding?

Sorry if I seem facetious, but it already has them...

I gotta agree...Are you serious?

Almost every tire on the road today are radials. Do they even make bias ply anymore?

Steel belted radials appeared in the early '70s and quickly became the standard. There were two other competing (if you can call it that) technologies at the time: belted pias ply tires and unbelted bias ply tires. The fuel economy saving of 10% would be over the unbelted bias ply tires.

The only things the bias ply tires had going for them were that they were easy to make and therefore cheaper, at least back when. The spread in price between basic bias ply tires and the comparable level of radial tire was often more than half again as much. Now bias ply tires of any sort are very rare, if they are made at all. The handling of bias ply tires was far poorer than the handling of radials, and the way the tire squirmed on the road made bias ply tires wear much faster and use your gas to scuff the tires.

All radial ply tires are belted to provide tread stability. Most are steel belted, but there are some tires belted with exotic fibers. As the others say, it is very likely your current tires are steel belted radials.

Mike

"Hachiroku" wrote in news:Fat4g.11$0v6.6@trndny05:

Hachi? Are you the same Hachi as from alt.autos.toyota?

Someone must have written that article 30 years ago. It is amazing how living long enough lets one see the cycles.

In 1972 the most popular passenger vehicle in the US was a body-on-from Chevrolet Impala weighing around 4,500 lbs. with a big V-8 and getting around 12-14 MPG.

In 2005 the most popular passenger vehicle in the US was the Ford F150 weighing around 4,500 lbs. with a big V-8 and getting around 12-14 MPG.

In the 1970s the arab nations decided to use their oil supply as a strategic weapon to hold the western world hostage and attempt to have it's way visa-vis Israel. By the late 1970s you couldn't give away that Chevy Impala. Will the same happen for the F150 and it's ilk?

How to get better fuel economy articles were all the rage and switching to radial tires was one of the common suggestions. About.com seems to have simply picked up some of that old information.

In the end the only thing which is going to change the oil consumption habits of US consumers is for prices to go high enough. How high is high enough? We shall see.

John

To you all,

I am serious, and I am not afraid to ask any questions (even it may sound/seem ridiculous to you) that I have no knowledge, esp. the questions are related to gadget which you guys have tons of knowledge.

I came from the country where a car is a symbol of wealth, a measure of political power and that country is far behind the U.S. about 500 years in auto technology.

Oh, by the way, thanks Mike and John for your detailed explanation.

Michael Pardee wrote:

Newhope wrote:

Your question isn't weird at all. I'm not sure how much gasoline economy can be attributed to radial ply tires, but tire technology has advanced a lot in the last few decades. Two features are prominent in design advancement. Radial plies and belts on the inside and rubber composition on the outside. This link will get you to a picture of a radial tire showing these features.

Because the cords which strengthen the construction plies of the tire run "straight" out from the center of the tire, around the outer diameter and back toward the center on the other side, they are called radial. This configuration reduces cross-cord flexing which keeps the tire cooler when turning under a load and puts all the strain parallel to the cords which is their strongest direction. Radial side walls can be made thinner than bias because of the strength inherent in the design which makes them lighter and more flexible. Lower unsprung weight makes the vehicle handle better and feel more comfortable. If the wear surface of the tire (inside the tread) were not stabilized, the tire would squirm and roll from side to side around the metal wheel. Steel belts are laid down around the circumference of the tire to provide this stability, add puncture resistance and improve tread contact. In addition, tire rubber compounds are so much better now that it is common to drive properly maintained tires more than 65,000 miles and

80,000 mile warranties are not rare. One of the coolest things about radial tire design is that it allows significantly smaller sidewalls. Bias ply tires used to be about 80% as tall as they were wide. 70, 60, and 50 series tires are common today with even lower profile tires available for higher performance. If your tires have lettering on the side that includes a "R," like 195R60x15 or 225SR50x17, you have radial tires

Hope this helps. Happy driving David