Inflation - too much too little or is it all bs

[vlamgat]

Originally Posted by rob_gendreau

I would hope you mean you'd accelerate to compensate for the loss of speed AFTER the blowout...not when it is imminent
Rob

Michelin has a video on Youtube that is quite specific in advising that upon the blow out, you floor the gas and then slowly lift off. You do not take your foot off the gas and absolutely do not hit the brakes. The idea is to manage the vector of forces arising after the blow out especially if its a front wheel where you need more thrust from the rear to counter the heavy pull towards the side that blew out. All my blow outs (3) have been on the same left rear. Which is starting to tell me that I am possibly over loading that side of the van. Which given that the driver, the fule, the a/c, the fridge, the rancho bed, the water and the in house elctronics are that side is a clue. Not that I can move any of it.

What I do not understand is why I was blow out free from 2006 through 2011 without any change in the config or equipment, same region, same temps, same speeds, same trailer, same hitch and Michelin E rated tires. The tires were new in 2009, rotated in 2010 and new again in 2011 after the first blow out. Two weeks ago I blew out first one of the new 2011s and the spare which was part of the 2009 batch. Neither were stored outside except when camping and towing.

So is Michelin going the way of all the other guys, quality down and price up?

[Scalf77]

I have a after market TPMS by PressuerPro http://www.advantagepressurepro.com/. I liked their unit as it could handle higher pressures than most. You can get versions that monitor your trailer also. The temperature data does not have much granularity, but it appears to work well, since I have it also attached to my computer, I really am monitoring the differences between tires as much as raw values. I usually try to make sure that one tire does not stick out in either pressure change or temperature change. The also have a free program that allows you to down load 60 days worth of data E-Tire. see http://www.sportsmobileforum.com/vie...654&hilit=TPMS for more details on my install.


greg

[vlamgat]

I have the same product but mine is the 2008 model. I ever installed it because I was concerned about sensor theft, bleed down and battery life from the sensors. Needlessly as it turns out and whatever the cost or implications of these factors, they are nothing like the damage of a blow out.

Mine will not log data but I am going to use it for the rest of the year to get a sense of whats going on and probably replace it with the new version next year. If Michelin lets me live that long !

[geoffff]

Originally Posted by vlamgat

Michelin has a video on Youtube that is quite specific in advising that upon the blow out, you floor the gas and then slowly lift off. You do not take your foot off the gas and absolutely do not hit the brakes. The idea is to manage the vector of forces arising after the blow out especially if its a front wheel where you need more thrust from the rear to counter the heavy pull towards the side that blew out.

I'm guessing you mean this video:

https://www.youtube.com/watch?v=lkwOE1yKY5c

This video is a bit repetitive and takes a long time to get to the point, but at about 2:45 it instructs as you describe above.

I have once experienced a front wheel blowout driving a full-size RV, and I never would have thought of hitting the gas.

-- Geoff

[vlamgat]

That's the one.

[edroid]

I have read all the tire inflation threads over the last several months, and my bottom line is this:

Since BF Goodrich does not publish a detailed chart for my AT's specifying various PSI at various weights (as recommended by many on this site), I will NOT deviate from the specified 60 psi front and 80 psi rear that came with the vehicle on the door post.

The potential liability scares me off. If I have a blowout, I don't want to try to explain to some trial lawyer how I "improved" on BFG's specs due to the advice on an internet forum.

Not much interested in rehashing it here, but there has been a massive monetary award due to a blowout on a Sportsmobile.

Also, a question for you commercial truckers out there: do you adjust tire pressure on your 18 wheeler trailers according to the specific axle weight of each load?

[vlamgat]

Good question and I think your perspective is on point. Especially as I believe the load ratings are seriously imperfect for conditions and the loads. And although Goodrich (and others) do not caveat their load rating by specifying whether there is an exception for towing, I beth they would if they were pressed. Some roads are in such poor condition that the variability of the static hitch weight must be considerable as the trailer bobs up and down with frost heaves overload breakage and water damage. The question is just how much safety margin do we need over the nominal load maximum. I am beginning to think its at least 30%? Put another way, if you tow, your rear axle on your SMB cannot excceed a 4000 lb static load (implying about a 7500 lb GVWR) without going to a higher load rating tire than the E most of us use.

[ANZAC]

Why would you think tire companies failed to account for dynamic load and a safety margin in their tire ratings?

[vlamgat]

I am sure that there is a margin built into their ratings but I do not believe its sufficient to handle the combination of all the things I list. In any event I just weighed my rear axle on a CAT scale and got a rude awakening.

[ANZAC]

Originally Posted by edroid

Since BF Goodrich does not publish a detailed chart for my AT's specifying various PSI at various weights (as recommended by many on this site), I will NOT deviate from the specified 60 psi front and 80 psi rear that came with the vehicle on the door post.

The potential liability scares me off. If I have a blowout, I don't want to try to explain to some trial lawyer how I "improved" on BFG's specs due to the advice on an internet forum.

If you used the 80 psi rear as specified on the door post and had different sized tires than Ford originally fitted (eg 245 75 16), it could be argue that you didn't follow BFGs inflation specs for the load carrying capacity.

What sized tires do you have? Did you read the other threads on tire inflation?