ST Tire Speed Ratings Revisited

**fcatwo** · 04-30-2006, 07:25 PM

In the process of browsing the Goodyear web site in preparation for replacing the 4-YO Goodyear Marathon ST215/75R14 tires on our 2619 I was delighted to find that it is OK to tow our TM up to 75MPH at 50psi instead of the previously believed 65MPH. Yes the limit is 65 at max load and pressure but they add that 66 to 75 is OK at 10psi above "recommended pressure for load". Our TM axle weighs 3,200lbs loaded and (WDH)-hitched and our tires are rated: 1870lbs ea @ 50psi, 1790 ea @ 45psi and 1660 ea @ 40psi. This means we are OK for 65 MPH @ 40psi and 75MPH @ 50psi. There is a caveat about not exceeding the wheel(rim) rating but that should not be a problem at 50 PSI since the origional tires are rated at 50psi. Check it out if the subject interests you.

**rickst29** · 05-01-2006, 12:26 AM

The new "higher speeds ARE possible" pdf which Frank read can be found here: http://www.goodyear.com/rv/pdf/marat...nfo_032806.pdf Goodyear indicates that you can go up to 10 PSI above the original max rated cold inflation (50 PSI in the case of the R14 tire), but I have no idea what the maximum "pressure for the wheel" is on our 2619s and 2720s. That would be an issue if you run with axle load higher than 3300 lbs, adding 10 PSI will put you over the original spec of 50 PSI max. Does anyone know how much "headroom" the 14" wheel has?

(Not relevant for me personally, I've got the 15" tires and heavy axle. Just a question for the general interest of other speedy owners.)

**fcatwo** · 05-01-2006, 11:00 AM

Rickst29

Thanks for putting up the link but I didn't read it the same way you do. I interpreted it to mean I could tow faster because I don't need the full 50psi max to safely tow our 2619 at 65mph. I'm not advocating that anyone exceed the tire's max pressure printed on the tire. I don't think it will cause a problem but that's just my opinion and I'm in no way an expert on such matters. There is a link to "weights allowed at various pressures" chart on the site.

05-01-2006, 07:31 PM

Thanks for the link.

I thought that the only Goodyear tire for trailers was the Marathon. I see that they make 7 different tires for trailers. When it is time to buy new tires, I see I will have quite a bit of research to do.