Tire Pressure

[WDD]

So.....

Previous owner put oversized tires on C 182 P model. 8.00 - 6 on mains, up from 6.00 - 6. On the nose we have 6.00 - 6, up from 5.00 - 5. I'm not using this off field, just normal pavement so not looking for low tire pressures to be used on sand, soft soil, etc.

The POH has the tire pressures for the original sizes, but that does me no good with these new ones. I can't find an STC in the log books, and Good Year doesn't list tire pressures as it's application dependent.

Any thoughts on how to come up with a good tire pressure goal?

 

[ArrowFlyer86]

So.....

Previous owner put oversized tires on C 182 P model. 8.00 - 6 on mains, up from 6.00 - 6. On the nose we have 6.00 - 6, up from 5.00 - 5. I'm not using this off field, just normal pavement so not looking for low tire pressures to be used on sand, soft soil, etc.

The POH has the tire pressures for the original sizes, but that does me no good with these new ones. I can't find an STC in the log books, and Good Year doesn't list tire pressures as it's application dependent.

Any thoughts on how to come up with a good tire pressure goal?

My mechanic had told me that tire pressure is an aircraft level specification (mine is published in POH, like yours), not an attribute that should vary by the tire itself. Asked after I had bought new tires and didn't know what to inflate them to lol. Curious to hear what others suggest.

 

[Dixiebluesky]

I would use the book pressure and see how it sits. Maybe make adjustments if needed but it should be nearly identical. Are they the same ply as original?

 

[Bell206]

I can't find an STC in the log books,

A number of tire upgrades were done under 337s vs STCs at one time. And I believe Cessna offered a Heavy Gear option to put 6.00s on the nose. Perhaps look in those directions for your answers.

My mechanic had told me that tire pressure is an aircraft level specification

FYI: You'll find in a number of weighing procedures its acceptable to deflate tires to level the aircraft.

 

[WDD]

I would use the book pressure and see how it sits. Maybe make adjustments if needed but it should be nearly identical. Are they the same ply as original?

Yes, same ply.

 

[Dan Thomas]

My mechanic had told me that tire pressure is an aircraft level specification (mine is published in POH, like yours), not an attribute that should vary by the tire itself.

The larger tire needs somewhat less pressure. The footprint of that tire is larger, and there is a relationship to footprint square inches to pressure in pounds per square inch. Too much pressure will decrease the footprint, giving less traction and wearing out the center of the tread a lot sooner.

Aircraft level specification? Lol. Most trike airplanes will sit somewhat nose-high with the pressures all set properly. Some more than others, like the Bellanca Viking:

 

[ArrowFlyer86]

Aircraft level specification? Lol.

View attachment 154504

To be fair, the POH does specify tire pressure (in mine, at least). He may have been simplifying it for my plebeian consumption so I don't overthink it

 

[Ed Haywood]

"Aircraft level specification" has nothing to do with leveling the aircraft.

 

[Stewartb]

So.....

Previous owner put oversized tires on C 182 P model. 8.00 - 6 on mains, up from 6.00 - 6. On the nose we have 6.00 - 6, up from 5.00 - 5. I'm not using this off field, just normal pavement so not looking for low tire pressures to be used on sand, soft soil, etc.

The POH has the tire pressures for the original sizes, but that does me no good with these new ones. I can't find an STC in the log books, and Good Year doesn't list tire pressures as it's application dependent.

Any thoughts on how to come up with a good tire pressure goal?

I believe your tires are approved by Cessna per the Cessna 100 series service manual.

 

[WDD]

I believe your tires are approved by Cessna per the Cessna 100 series service manual.

For the win.

Didn't occur to me that it would be a Cessna approved tire size. Inside the Service Manual I found the tire pressures for the oversized tires, and they are indeed less than the standard size. Much obliged.