Tire pressures 2012 King Aire

[drdonny]

Any recommendation on tire pressures on bus of average weight with full wall slide?

Thanks

[Sky_Boss]

Originally Posted by drdonny

Any recommendation on tire pressures on bus of average weight with full wall slide?

Thanks

I'll beat everyone to the punch...tire pressure is based on corner weights. There are too many variables to say one FWS coach has the same corner weights as another. Sorry if you knew that already.

In the interim, I would use the tire pressure outlined in the plate next to your driver's seat. That plate will have tire size, pressure and axle weight information. Those "standard" pressures should normally be higher than you will need once you get an accurate weight. With a beautiful rig like that, you may not notice much difference in ride and handling between standard vs optimal.

Enjoy the new ride.

[nforus]

Hey Doc,

We weighed ours at the factory with full fuel, water, contents, and occupants,and the tire pressures listed on the label next to the drivers seat were consistent with what we saw on the Michelin tire pressure chart. 125# front, 85# duals, 115# tag.

[slabman]

Interestingly, the King now has less CCC than the Essex. Same tires up front with more tare weight on the King. Who'd a thunk it?

[Route 66]

The weight of all of those nice features add up!

[Sky_Boss]

Originally Posted by nforus

Hey Doc,

We weighed ours at the factory with full fuel, water, contents, and occupants,and the tire pressures listed on the label next to the drivers seat were consistent with what we saw on the Michelin tire pressure chart. 125# front, 85# duals, 115# tag.

WOW! I guess that I'm most surprised by the tag compared to the duals. I suppose the rear bath and engine stuff really puts weight on those tags but I would still think there would be more weight on the duals.

[FlyingDiver]

Originally Posted by nforus

Hey Doc,

We weighed ours at the factory with full fuel, water, contents, and occupants,and the tire pressures listed on the label next to the drivers seat were consistent with what we saw on the Michelin tire pressure chart. 125# front, 85# duals, 115# tag.

I believe your K3 chassis has the same tires (and weight limits) as ours, in which can you should never have 125# in the front. According the the Michelin chart I have, you would need 10,500# on either side which would be over the 20,000# axle limit. Unless you're really unbalanced, I suppose. We can't get our front axle anywhere near the weight limit, even with a full diesel tank. We're currently running 110# in the fronts, as our heaviest front wheel is about 9200#.

Also, our fronts had 120# or 125# when we picked it up from the factory. Ride quality was horrible. As soon as I got the front wheels weighed and dropped the pressure to 105# (which is what the chart called for at that time), the ride was so much better it was amazing.

WOW! I guess that I'm most surprised by the tag compared to the duals. I suppose the rear bath and engine stuff really puts weight on those tags but I would still think there would be more weight on the duals.

Actually, it's hard to get the mains above 85#. The axle limit is 20,000#, and the specified weight limit for 85# is 11,680#. So you need to be pretty much at max axle weight and very imbalanced to get one side over 11,680#. We're running 85# on the mains as well.

Not sure how you would get to 115# on the tag, unless they raised the axle limit since '08. You need to be close to 8,000# on one side (of a 14,000# axle) to need 115#. We're currently running 95# (just under 7,000# per side).

[slabman]

Aaaah!...but do you have 16 batteries...UP FRONT? That change has shifted a lot of weight forward. But you are correct in that 125 sounds horribly high. They put the max. 125 in those fronts as a cya measure, then its up to the owner to figure out how much less he needs to go with. With those 365's up front I run 110 also....a BIG difference in ride compared to 125. And yes, its pretty difficult to max out those rears....85 seems to be about the highest one can justify. Wonder when the Industry will move to those extra large single tires on the drive axles?

[nforus]

Originally Posted by FlyingDiver

I believe your K3 chassis has the same tires (and weight limits) as ours, in which can you should never have 125# in the front. According the the Michelin chart I have, you would need 10,500# on either side which would be over the 20,000# axle limit. Unless you're really unbalanced, I suppose. We can't get our front axle anywhere near the weight limit, even with a full diesel tank. We're currently running 110# in the fronts, as our heaviest front wheel is about 9200#.

Also, our fronts had 120# or 125# when we picked it up from the factory. Ride quality was horrible. As soon as I got the front wheels weighed and dropped the pressure to 105# (which is what the chart called for at that time), the ride was so much better it was amazing.




Actually, it's hard to get the mains above 85#. The axle limit is 20,000#, and the specified weight limit for 85# is 11,680#. So you need to be pretty much at max axle weight and very imbalanced to get one side over 11,680#. We're running 85# on the mains as well.

Not sure how you would get to 115# on the tag, unless they raised the axle limit since '08. You need to be close to 8,000# on one side (of a 14,000# axle) to need 115#. We're currently running 95# (just under 7,000# per side).

LF 9310 lb
RF 10270 lb
LR 9140 lb
RR 8695lb
LR2 6350lb
RR2 6295 lb

I pulled up the Michelin chart and it looks like the Newmar techs were on the side of safety when they told us to run the pressures listed on the drivers seat label as recommended by Newmar, and I can reduce by a few pounds. We purposefully weighed as heavy as we could, full fuel, full fresh water, 4 occupants etc. and we also have to account for the 16 house batteries, freezer ,and 2 TV's that are partially loading the front axle. Since we never run with more than 15% fresh water, we've got some room to move on pressures, but I'll trade a little rougher ride over an under-pressure blow-out anyday!!

[FlyingDiver]

Originally Posted by slabman

Aaaah!...but do you have 16 batteries...UP FRONT? That change has shifted a lot of weight forward. But you are correct in that 125 sounds horribly high. They put the max. 125 in those fronts as a cya measure, then its up to the owner to figure out how much less he needs to go with. With those 365's up front I run 110 also....a BIG difference in ride compared to 125. And yes, its pretty difficult to max out those rears....85 seems to be about the highest one can justify. Wonder when the Industry will move to those extra large single tires on the drive axles?

I forgot about the battery re-location. Yeah, that would drive the weights in front up. I can see 110 or 115 then.

I know some manufacturers are putting 365s on the tag now as well as the fronts. Seems like you could easily run these units with 6x 365s instead of a mix of 365s and 315s.

[FlyingDiver]

Originally Posted by nforus

LF 9310 lb
RF 10270 lb
LR 9140 lb
RR 8695lb
LR2 6350lb
RR2 6295 lb

I pulled up the Michelin chart and it looks like the Newmar techs were on the side of safety when they told us to run the pressures listed on the drivers seat label as recommended by Newmar, and I can reduce by a few pounds. We purposefully weighed as heavy as we could, full fuel, full fresh water, 4 occupants etc. and we also have to account for the 16 house batteries, freezer ,and 2 TV's that are partially loading the front axle. Since we never run with more than 15% fresh water, we've got some room to move on pressures, but I'll trade a little rougher ride over an under-pressure blow-out anyday!!

I would get those front weights checked again. The batteries are on the left, so what's driving the RF weight so high? Almost 1000lb difference between the sides on the front is a lot. My right side is 750 heavier than my left, but I don't have batteries on that side, where I do have the steps, freezer, and my heavy tools on the right.

[nforus]

Originally Posted by FlyingDiver

I would get those front weights checked again. The batteries are on the left, so what's driving the RF weight so high? Almost 1000lb difference between the sides on the front is a lot. My right side is 750 heavier than my left, but I don't have batteries on that side, where I do have the steps, freezer, and my heavy tools on the right.

I thought the number was strange too, but i was there when they weighed it and have the print-out from the scales. Maybe the 4 fellow Kamp Newmar folks who agreed to pose as "occupants" so I could watch the weighing were all sitting on one side of the coach and might need to go on a diet

We'll be back in Petosky later this month and it will be interesting to see if the KA owners up there have weights for their coaches.

[jtovo]

I just weighed my Essex & the front axle was 18,300, when I took delivery the tires on the front axle had 125 & according to the Michelin chart the pressure on the 365 can be as low as 105.
There is a world of difference in the ride at 105.