Recent content by tireman9

KNAP Not sure what you are looking for concerning "inside" info. Can you be more specific? 37 yrs Tire Eng. Designed basic rain Firestone for CART. SCCA & IMSA Pro & Am. Set lap records at 6 different road courses in '89-91.

Since some of the comments go to fuel economy you might be interested in a recent test I ran. 2006 Hyundai Tiburon V6 with Firestone Wide Oval performance tires 215/45R17 87W with 4000 miles wear 30.0 psi cold. Warm up 3 miles. Ambient 86°F Cruse control speed set at 63.4 mph checked with...

Good job CAPRIRACER of covering the complex topic of Regulatory and Association requirements of load and inflation. Your long reply of Aug 15 should be required reading for anyone making a post on tire load or inflation. Minor bit of info re "MAx inflation" on the sidewall. In the past (about...

I think it important to separate the effects of ride & handeling into at least 2 different areas. One is for vehicles with completely adjustable suspension such as race cars. For production based, even with some mods to suspension there are some other items at work which can make what is...

We seem to have a couple different thought trends working here. One being the theoretical improvement in vehicle handling based on the assumption that wider tires have a larger foot print. Sorry but in general this is not the case. The total contact area is essentially the same for a wide range...

To CCW Not sure what you mean by "Nominal". In years past ( 70's) with bias tires "Nominal" meant 26 psi. The proper inflation should never be lower than that specified by the vehicel manufacturer and never higher than the max stated on the sidewall of the tire. I personally run 2 to 3 psi...

To Zeusfaber No, Vehicle engineers do not try and keep inflations at the minimum. Also you have the handling response backward. Higher inflation is better for response and increases cornering force. The vehicle recomended inflation is a compromise between soft ride i.e. low inflation vs good...

Jadcock I am sorry. I mistook your name in bold in the message from ccw. All my comments were concerning the 25 Aug at 17:33 post from ccw. 37 yrs Tire Eng. Designed basic rain Firestone for CART. SCCA & IMSA Pro & Am. Set lap records at 6 different road courses in '89-91.

Jadcock Sorry to burst your bubble but compound has a lot to do with wet traction. We use special compounds that allow the tread to accomidate the microscopic irregularities in the road even when wet. The article is a good explanation of what is probably happening at that level. Re the...

As I pointed out in my earlier post, the book "Engineering Design Guide" is about 200 pages so I really can't go into all the details of the different formula for different size or application tires. K does change as well as other parts of the equasion for lower aspect ratio tires. In general...

A is the aspect ratio i.e. 75 or 60 H is the section height ( OD - rim dia)/2 Sd is calculated. For S70 you can use the nominal section width i.e. 235 or 205 etc. It may be easier to develop a formula where P is the variable for your current size tire. With 26 psi as the minimum and...

In the states, Europe, Japan and South America most OE tires are not the same as the replacement tire of the same name with the exception of GM TPC tires which are the same thing till the vehicle is out of production. The performance spec is written by the vehicle mfg with ride, fuel economy...

GregLocock and others The problem with solving the problem "once" is that tires are not all alike and do not transfer the loads to the rim in the same manner. Somce of the tire variables other than tire size or tractive force capability or stiffness or other general performance characteristice...

Ok, I guess a little more background is needed. First you need to understand that there are number of "Associations" that most of the world's tire companies belong to. Second you need to know that the current formulas used by these associadions have been and are still in a state of continuous...