new tires

[Tim Bookmiller]

reply to clifford and RJ I do  not have a 4104 I have a 4106 -now wondering about tire size -I had Toyo 12r 22.5 and replaced them with 315/80r/22.5  am I out of the ballpark on tire size ??

[DoubleEagle]

reply to clifford and RJ I do  not have a 4104 I have a 4106 -now wondering about tire size -I had Toyo 12r 22.5 and replaced them with 315/80r/22.5  am I out of the ballpark on tire size ??

I would say the two sizes compare closely. According to Continental specs, their 12R 22.5 has an inflated diameter of 42.7 in., and a revs per mile of 487. The 315/80R 22.5 is 42.4 in., and 491 revs per mile. My 05 Eagle came with 12R 22.5's, so I do not see why Clifford would say 315/80R's are so big, 12R 22.5's were used on a lot of buses. The width might be the only meaningful difference.

[kyle4501]

Based on the advice from a friend who works at Michelin corporate --
I run tire pressures as much above minimum as the ride quality will allow (of course never exceed tire or rim maximum psi rating ).
In so doing, I will have more time to catch a slow leak before tire damage occurs.

I also have Crossfire tire pressure indicators on the rear duals - lots easier to keep an eye on the inside tire during a walk around inspection.

[niles500]

Funny story, I used to worry about my steer axle weight and the 9000 lb Michilens until I read the Alcoa's stamped at 7500 lb max, your never stronger than your weakest link - fwiw

[TomC]

315/80 is an expensive tire. Why not run a 12R or even a 11R. Please tell us your axle weights when you weigh the bus.

[luvrbus]

Doesn't the Feds require all vehicle manufacturers to post air pressure and size of tire on the data plates ?

[Dave5Cs]

Yes but being they are no longer in service vehicles that won't be the same. take stuff off or add to it.

[RJ]

Doesn't the Feds require all vehicle manufacturers to post air pressure and size of tire on the data plates?

Clifford -

IIRC, nothing required on pre-1977 vehicles, when the FMVSS rules went into effect.

Tim -

Am I out of the ballpark on tire size ??

The magic number for your 4106 is 495 revs per mile to give performance like the factory designed into the powertrain.  What's the rev/mile spec for the new 315s?  That will answer your question.

FWIW & HTH. . .

[luvrbus]

Thanks RJ but since Eagle has always had the tire data plate I thought all buses would have had it.

If the poster installed the 315's on a 8.25 wide wheel they are not going to ride real good anyway