Michelin Load & Inflation Tables

[mrkane]

Michelin tables show 12R as 485 rev per mile, 315 as 492 rpm and 295 as 503 rpm.

Last time Sleipnir was weighed, both waste tanks were nearly full, as was the fuel tank. Steer was 12220/13200 GAWR, drive was 23,960/23,000 and the tag was 8380/12,100, total 44,560/44,000 GVWR. Of course, I rarely operate on the highway with full waste tanks, and the diesel tank doesn't remain full for long, either.

The load tables show 105 PSI is required for the 295/80s and 95 PSI for the 315/80s to carry 14,000 lbs. Using 295s on all axles would seem to give the advantage of being able to swap between any position, while also avoiding spacing issues on the drive axle.

It is unclear to me whether up-sizing the tires brings real benefit with low-capacity wheels, such as mine. Granted the 295/80s are an uncommon size, but I was able to get one in the middle of SD last fall to replace a damaged tire, with no waiting (except for the tech to drive ~150 miles from Rapid City.)


M.R.Kane
1987 PT40 'Sleipnir'
currently near Elmo, TX