Tire Pressure ?

[Ocsmb]

Got it. Found a Cat Scale by my house. $10, open 24hrs and you can get weight per axle.

[chromisdesigns]

Originally Posted by Ocsmb

GAWR is the max weight you should ever have, regardless of what has been done to the vehicle. If your SMB is over GAWR front or rear, you need to either re-distribute some of the load, get rid of some toys, or both!

[rob_gendreau]

I tried to get some folks to let me corner weigh my van at the track, but we feared it would be over the scales capacity. I sorta think I’m light on the passenger side.

As this isn't a sports car, any utility in setting pressures different side to side? Seems to me that it would be useless in the van's case.

Rob

[rob_gendreau]

That 15% extra seems like a lot. I've overinflated to seek better gas mileage on a street car, and didn't like the result. On the van it might not be as noticeable as a car, but still.

Do you add that in case you load up more stuff in the van?

Rob

[Ford_6L_E350]

Originally Posted by chromisdesigns

GAWR is the max weight you should ever have, regardless of what has been done to the vehicle. If your SMB is over GAWR front or rear, you need to either re-distribute some of the load, get rid of some toys, or both!

Or upgrade the suspension. I replaced the ~6500# rear axle with a FF 7800# axle from an E350 cutaway with the same frame. And the F350 front axle is rated higher than the old twin I-beam front end - not to mention better brakes.

Mike

[rob_gendreau]

Yeah, I also got a Ford F350 front end swapped into my van. Gives it a higher capacity up there, 'tho I don't seem to need it. I'm closer in the back, but I added a leaf and beefed up the shackles.

I'm curious though about official weight ratings. I think the sticker on my door from SMB lists the same weights as Ford does on the door frame. If one upgrades, is there a way to tell the new amount? I realize we're not gonna get cited for overweight, but I wonder if it's ever come up. I think someone mentioned in another thread here SMB wouldn't do something to their van because it would exceed the weight rating.

Rob

[Ford_6L_E350]

Uprating the capacity is up to the upfitter. Salem-Kroger had the engineering talent to rerate my conversion. And to list it on the tag they placed on the van.

Mike

[rob_gendreau]

Hmm. Mine's a Salem Kroger as well, and I don't have any such thing The tag they added puts nothing on aside from their (defunct) contact info, unless I missed something. I just have a little plate attached to the plastic on the doorstep.

[Ford_6L_E350]

That's where my plate is also. I asked about raising the ratings and Craig told me what he could do.

Mike

[geoffff]

Originally Posted by Pschitt

If you inflate your tires to much, the breaking distance will increase, the traction will be reduced and your mileage of the tire set will decrease a lot! 10% over pressure will decrease mileage of the set more than 15%, 15% more than 25%!

With overinflation comes decreased traction & increased braking distance -- sure -- but I don't see how it would *hurt* gas mileage. In fact, higher tire pressures than safety would warrant are used in "supermileage" competitions.

In any case, if you're overinflated you're not touching the ground with your whole tire tread width. Try the chalk trick to check:



On my 9500lb van, I find that at 55 PSI, the very outer edges of my tires stop touching the ground -- but that could be aggravated by having somewhat uneven tread surface, from cornering wear and driving for long distances while aired down (Baja roads...).

-- Geoff