Date: Sat, 22 Nov 2014 10:44:38 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Nokian tire sidewall cracks-tire pressures and reading the
placard.
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The 185R14 and 205/70 noted below do not use the same pressures. The factory recommendation of 30 front, 40 rear is for the 205/70XL and in my opinion is too low for the front. The 185R14 needs to operate at a higher pressure for a given load for a number reasons.
The major concern for a tires ability to carry a load is heat generation. Heat comes from the friction the tread on the road and the flexing of the tread and sidewalls. Inflation is also a compromise situation. More pressure does mean lower rolling resistance and less heat generation and even better steering response but it also means less traction less ability to absorb road defects.
The heavier duty tires such as any load range C or D at any given size will need to operate at a higher pressure due to heat buildup of all those extra plies. More material flexing the same means more heat.
Even the XL passenger tires such as the 205/70-14XL need slightly higher pressures for a given load than a passenger tire of the same size. For proper inflation of the heavy duty tires you really want to look at the load-inflation table and know the real weight on the tire or at least axle.
The 205/65-15 load range C tire is real close to the original diameter of the 185R14. It is a heavy duty load range C tire so the load-inflation table would be a real good guideline. But since size as construction is close to the 185R14 I would go with the placard recommendation for that size knowing the increased width will give slightly more reserve.
With modern day radial tires you really don’t see obvious tread wear issue with inflation unless you are way off base.
Just more thoughts.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Loren Busch
Sent: Friday, November 21, 2014 2:52 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Nokian tire sidewall cracks
RE: Nokian Tire Problems and Tire Pressure First, pressures. The pressures on the placard on the door are for the tire sizes shown on that placard, either 185R14 or 205/70R 14. When you go to different tires then don't go by those pressures.
Re: Nokians
For nearly three years I have been running the Hakka WRC 205/65 15's on my
'90 Westy. When they were installed Peter at Van Cafe pointed out that he had a customer with a set of those with sidewall cracking. They had been run at the pressure recommended on the door plaque, 30 front 40 rear. I went with 48 front and 50 rear. And that is what I have run for just under 30k miles now. And no sidewall problems at all. And perfectly even wear (with X roatation every 3-5k miles) It is very simple to check tread wear for even wear across the tread.
Uneven wear is telling you that you are over or under inflating. And wear on one side says alignment problems. Pretty straight forward. And even more important for you Syncro drivers that need even wear/equal tread all the way around.
