Running tires lower than Micheline spec ?

deprived wrote:

But if running a bit low increases the chance of a blowout, I'm not sure this is such a good strategy.

Only you can make that call ......for YOU.

The addition of the toad might have leveraged some load OFF of the front by putting some downward pressure behind the rears.

If that is the case, the 5 PSI adjustment probably is perfectly fine.

I think some people worry too much.......about a LOT of things.

Sfla2 wrote:
cause most c are near max ccc,esp if u have slides

That is also true. Max or worse!

most ford 450 "c" run 65 frt 80 rear which is max for thast size tire,can't go wrong running max,cause most c are near max ccc,esp if u have slides

Sam Spade wrote:


And since this is a class C, I still think that obsessing over tire pressures is....obsessive..

That is probably true. There are some purists who insist you will die instantly in a horrible crash if tire pressure isn't NASA-perfect and perhaps I've paid those opinions too much mind.

Well, maybe part of the issue is I've misunderstood the weight/psi for my situation. The motorhome is pretty well balanced with 2300 pounds even on both front wheels. For my tires on a E450 chassis, I think the chart indicates 65 psi.

I've already added a 2014 front end, positive caster, steer-safe, air bags, trac-bar, sway bars, FSD shocks, etc etc snd it has helped handling enormously . But with the addition of the toad, the handling is a bit trickier. Not bad, but a tad tricky.

Just to see if it made any difference, I dropped the psi by five pounds to see what it felt like. The steering felt more "grippy".

But if running a bit low increases the chance of a blowout, I'm not sure this is such a good strategy.

j-d wrote:
It's an E450.

The E450 has an alignment defect that needs to be corrected if you feel the steering is wandering; probably applies to all models that use it for a chassis. There are threads on here about it. Did it on mine and it made a WORLD of difference. Doing a search for caster or camber should find it (sorry I don't remember which). Maybe someone else will.

And since this is a class C, I still think that obsessing over tire pressures is....obsessive. 80 rear; 65 front should serve you fine even if you go up a load range, unless you have done something to drastically alter the total weight or front to back distribution.

The Micheline ties are too aggressive tread. You can move the outer tread with two fingers. That's where you get the squirrly front end tire roll.

I put a full new set on my C and my handling went from great to suck.:( I am so sorry I put new tires on it.

I run the front tires 10 lower than the rear. I think that's what most of do.

It's an E450. On ours, tire shop disregarded my request and set all six at 80. Nearly lost it on the road, lowered to 70 (hot) on the side of the road and it got much better. Weight/Load indicated 60 and change. Drove OK. Upped to 65 and it's the best to date. We have 4500+ on the front axle.

deprived wrote:

Other than tire wear, is there and danger or disadvantage to running the tires a little bit low?

What kind of a rig is this on and how do the pressures compare to the original pressure recommendations for stock tires ? And are they the same load range tires as original ?

Yes running them low can be a problem but determining what really constitutes low can be a problem too.

Ford E350/450 chassis have a problem with the alignment settings.

Be aware that using your actual wheel position weight, selecting the heavier wheel position on that axle and going to the inflation table gives you the MINIMUM PSI FOR THAT LOAD-- all tires on an axle to have the same PSI dictated by the heavier wheel position.

Yes, the big danger is a blowout. Carrying less than recommended pressure= (yes, is the same as) being overloaded.

You do not mention what chassis you have-- please post.

And, by "Squirrely" please describe more fully.