Hey all,
TIRE PRESSURE: Agree with Blue-Go.
Go with tire pressure ratings on the tire.
Had an alignment done at an Alignment Shop recently because there was a slight pull to the right (since I bought "The Nook" in July 2021). I was a bit taken aback when I took the RV home and had a good look at things. The shop had inflated the front tire pressure to 80 PSI on both sides.
So a quick call to the Alignment Shop got me a quick explanation (and a little SCHOOLONG). The tires that are on this Chinook (Cooper) are rated for a max cold fill PSI of 80. Ford door jam sticker shows fronts to run at 65 PSI and rears to run at 55 PSI. The shop said the profile of the tire at 80 PSI will give an even wear (all alignment things being correct) and that if the ride is too stiff, I shoulda, coulda, woulda play with (decrease) the pressure till I am happy ... but again, I need to be clear that the profile of the tire at lower (softer) pressure would likely wear the shoulders of the tire faster than the center tread.
TIRE ROTATION: Not to further confuse anyone (including myself) but, I've got a tire rotation question. While reading the Ford Manual, I see that it calls for only rotating the front tires. To me, that means we leave the rear tires in the rear where they were positioned when initially installed. In other words, Do Not Rotate the rear dual tires.
This is different from every car or light truck I've owned in the past 51 years.
WOW. So, what say you ??
Cheers
N~
**** UPDATE 2022-02-10 ****
Please disregard my statement in the earlier post on this thread: "Go with tire pressure ratings on the tire."
Wow - Am I ever getting SCHOOLED - in a variety of ways but gotta say - this forum is very cool and super helpful on many levels. Who knew that there could be so many opinions, experiences and calculations for TIRE PRESSURE ... Right !! After reading the additional entries on this thread, doing some random searches on the internet and contacting the mfg. of my tires, Cooper Tire , I have a better appreciation for tires, tire pressure and what tire pressure means to RV handling and safety.
To Blue-Go: Thanks for being quick (and kindly) responding to my post. Your post got me to realize I did NOT really understand what I was reading. I did however start all this with the feeling that the Alignment shop inflating my tires to 80 psi was not right. Fortunately, I follow my gut on such things and that lead me to a new understanding.
Here is where things stand for me now:
My 1999 Chinook Concourse (Trail Wagon) Tire Placard states recommended tire pressure : 65 psi front and 55 psi rear.
My Tires: Cooper - Discoverer HTP LT225/75 R16, Load Rating E, Max Cold Inflation Pressure 80 psi.
Vehicle Placard: RV Mfg companies are required to put a placard on the vehicle with the tire size and pressure ratings (along with some other stuff). So I went out to the Chinook at 10:25 pm last night and sure enough, Trail Wagon had a (HARD TO READ) sticker on the door. Originally, I looked only at the FORD sticker and assumed that it was probably not correct because Ford had delivered the E-350 "Cutaway" to the RV Mfg and would not know what (weight) would be put on the the truck frame, but it turns out the the Ford and the Trail Wagon placards show the same PRESSURE figures.
Cooper Tire: I called Cooper Tire and the rep pulled up their charts. She said that according to the chart they use, the front tires would be set at 40 psi and the rears a little less. At that point she stopped the discussion and said very clearly, USE the pressures on the RV mfg's placard.
Considering Ford and Trail Wagon both call out the same tire inflation numbers, that's where I will return my tire pressures at this point.
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The following information was copied from the web site:
https://vehq.com/rv-tire-pressure/ and presented here as information only.
What Happens if Your RV Tire Pressure is Too High or Too Low?
Driving your motorhome or towing your travel trailer or 5th wheel with the wrong level of tire pressure can lead to all sorts of problems, affecting your stability, ease of ride and even gas mileage.
When RV Tire Pressure is Too High
The over-inflation of tires makes the sidewalls and tread of the tire harder than normal. This can limit the performance and traction of the tire. Also, it may cause uneven tire wear. Plus, over-inflation will lead to a harsh ride, wobbly handling in the wind, and reduced braking effectiveness that is especially reduced on wet roads. If you're towing a travel trailer, it could also lead to sway issues. Read more on how to prevent travel trailer sway in this post (see
https://vehq.com/rv-tire-pressure/ ). Also, tire pressure that is too high can cause a slight increase in gas mileage by reducing the rolling resistance of your tires.
When RV Tire Pressure is Too Low
Most tire blowouts are caused by underinflation. Underinflation will force tires to come into contact with the ground more than properly inflated tires would. Read more on RV tire blowouts (and how to prevent them) in this post.
To be more specific, the sides, or shoulders, of tires flex more when under-inflated which produces an excessive amount of heat, and excessive amounts of heat lead to tire failure.
If your tires are under-inflated by just 10 or 15 psi, then the temperatures on the sides of the tires can reach 200 degrees Fahrenheit.
Is High or Low Tire Pressure More Dangerous?
There is a simple answer to this. Low tire pressure is more dangerous than high tire pressure.
Low tire pressure leads to dangerous blowouts while high tire pressure is generally less dangerous. This is true as long as the tire pressure is below the "maximum inflation pressure." If you go over that, you could end up with a blowout as well. Of course, there are other safety issues associated with high tire pressure, such as increased sway when towing.
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Final Thought:
This has been a learning opportunity for me ... and caused me to think differently about tires.
