OK, I see. You're comparing a truck tire on a motorhome of unspecified (probably unknown) weight and tire capacity running in the heat of the day in the desert with unspecified (unknown?) pressures to the buildup of heat on a 3800# Fusion that's within the factory specification for weight and sidewall pressure. Which travel happens to be in Indiana. Got it.

Just pointing out that there can be a lot of factors that make it appear that a tire is at fault when it may actually be something else.

You also attempt to demean my knowledge by referencing the Ford/Bridgestone/Firestone issue with their SUV. I'm going to let that go, figuring that you don't know any more about the issues that lead to that than you do about the stress you were putting on the tires on your motorhome or the risk of running 40psi in a Ford Fusion Hybrid tire.

I've not advocated anything that is out of spec from Ford and Michelin.

BTW, the speed rating on the tires of my Fusion is "V", which is good for sustained speeds up to 149 mph. (Fat chance!)

http://www.tirerack.com/tires/tirete....jsp?techid=35

You might also be interested in this chart which shows that, when tires are being driven at high(er) speeds, pressure should be increased (which reduces flex which reduces heat...). If you don't think I'm an expert, maybe you'll want to take these guys on. I count some of the experts there as my friends and competitors.

http://www.tirerack.com/tires/tirete...adj_Vspeed.jsp

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Bob

 

Like I said before I was just trying to help by giving you something to think about but now I see you are a expert, at least in your mind and this is the last time I will try to help you as you are a legend in your own mind. Sorry I tried helping but I won't make the mistake again.

 

In those areas where I don't have expertise, I find it best to either listen or ask questions. Note that my question that started this thread was one of those.

You just happened to comment on a side matter as though you had expertise when you later admit, you didn't. In that area, it just happens that I do, but someone else reading the thread might be needlessly alarmed by your comment.

Hopefully, you learned something in the exchange and related hyperlinks so will have more expertise next time.

Bob

 

Folks, if you can not trust the specs on the side of the tire that the tire manufacturer put there then who or what can you trust?

Following the max tire inflation on the tires sidewall and NOT the dumb sticker on the door or the glove box is always the best practice IMO.

Nitrogen while a bit more$$$ may turn out to be a bit better in the long run.

As for Motorhomes blowing tires in the heat of the desert, this to me is not surprising. These RV's sit for long periods of time the tires crack and age due to neglect and more often than not the RV is majorly overloaded too. Put in more air and add heat and there you go. Or is it blow?

Just another interesting story with not enough hard data to help with anything. Too many variables and no facts to help arrive at any sound conclusion. The take away here is ....

Tires do deteriorate over time. Keep them inflated within the side wall stamped PSI's. Never overload the vehicle beyond it's max rating. Never drive faster than the tire is designed for. Rotate and balance regularly. Keep you car properly aligned.

Common sense things but often overlooked.

Now lets get back to our regularly scheduled program.

 

AllenF:

Following your post, I increased my tire pressure from 35psi to 40. Even though I have been less focused on increasing mileage via driving traits, my mileage (to/from work, the same stuff as usual) has increased by at least 2-3 mpg. That surprised me that it was that much, especially since I've been less observant of other good habits. Thanks for your original post!

Bob
PS. I still don't have the nerve to crawl away from stoplights during rush hour just to keep it in EV mode. "Peer pressure"... maybe I need a "RoadRageFunSign".

 

Good to hear your results.
Inflating to higher PSI's does have one negative impact. The ride is rougher. How rough is subjective.
Playing with tire pressures are more or less free. One thing to remember, try to keep the pressures the same at all 4 tires, as differences can affect handling. One tire on the front down a few pounds can cause the car to handle like it needs a front end alignment.

As for stop light crawling...

Watching your instant MPG's and accelerating resonably rather than too slow or jack rabbit style will probably return good results. The harder the start the heavier the battery assist. This may seem wrong as to mpg's but in fact MAY be better than crawling or nearly the same and still making the guy behind you like you a lot more. Saving an oz. or 2 only to have him shoot you is not a wise choice IMO.

Try brisk acceleration to say 47mph then coasting down to say 43mph then gentle EV up to 45mph. Watching the green bracket can tell you how much throttle you need to get to EV mode. This may be better than the crawl or the same as the crawl. Compare slipping it into neutral over just coasting in gear. Which one goes farther with less resistance? Always try to stay in the far right lane so as to allow Ricky Racer to go around you.

Over time you will find the sweet spot in most common situations. This will allow you to get the best MPG's while also driving more like a normal Larry Leadfoot. Just kidding. There is no way Larry will be happy with our more MPG concious driving techniques. But once gas gets back to $4+/ gallon then even Larry and Ricky will slooow down and follow us as it will pay for them to do so.

 

You peeps getting over about 42-43 must NOT live in California. We have MTB and other additives that lower mpg. In California, with a recent average daytime high of about 94F, tough to do much better than 40-41, which is where I am right now.

 

Bob the next step is to have your ex wife get out and push the car. This can really help with mpg. In addition to that, I have my two pomeranians pulling the car uphill. It's not much, but every little bit, every 8 lb little bit, can help. Finally--screw the max sidewall pressure! I have just removed my tires completely and now just ride directly on the wheels. Sure, it's a bit noisy, but man, we are talking low drag!