[Glenn and Laureen]

I have Sumitomo ST 719 tires, which I had the Les Schwab folks in Gridley, CA put on the morning after we bought the coach. They are 11R22.5. They will age out before they wear out with our limited driving each year.

I don't recall exactly what rpm I see at 60 mph. I think around 1700-1750. Will check it a week from next Monday when I drive the coach over to a shop for an oil change. I do know that at 60 mph with cruise control on I feel like we are just floating along with no stress.

[Mageeacres]

Glenn, That’s great. If you’re at 1860 rpm at 60 mph then you have a 3.70 rearend ratio with 11r22.5 tires. Thanks for the information.

[whatsnewell]

I've got 22.5 tires, and at 60 mph I'm around 1800 RPM's....give, or take.

[Mageeacres]

Clarke, I presume an Allison ht750 transmission ?

[whatsnewell]

Not sure of the model number, but it is a 5 speed just like Glenn's. I do have the manual, so I'll have to pull it out and verify the model number. I'll let you know for sure.

[Mageeacres]

If it’s like Glenn’s, then we have the same one. 1:1 ratio in 5th gear

[Glenn and Laureen]

Mike, my 1984 has an Allison MT654 5 speed transmission. Don't know about Clarke's.

[Guy]

Usually, Classics with a 6V92   got 5 gears, and 8V92 got four gears. The thought being that the larger engine had enough torque with just 4 gears.

[Fulltiming]

Guy is correct. Typically the 8V92's had the HT740.

[Mageeacres]

I found this in the original paperwork... too cool!!

It’s an original geared road speed curve graph. It’s for the 11r22.5 tires.