Recommended Pressures for Kuhmo 195/14

[greentrail]

Hi guys,

I had recently switched to the Kuhmo tires to up the load headroom but found running the tires at the max 65 psi caused a "harsher" ride for the trailer. I contacted Kuhmo usa for guidance and they promptly replied with the recommendation of running at 55 psi. They said that would give a load rating of 1832 per tire which would give a total of 3664 which would match the 3500 lb rating of the single axle on the 2720 and give a little softer ride.

Thought you guys might be able to use this information.

[Bill]

A rating of 1832 pounds is actually a bit less than the rating on the factory-original 14-inch Marathons.

Bill

[ShrimpBurrito]

That's rather fascinating. I have 205/R14 Kumhos and consulted with Kumho as well for their load ratings at specified air pressures. They in turn sent me an Excel spreadsheet for pressure / load rating correlations for both the 195's and 205's, which is attached as a PDF. 55 psi isn't even on the chart, but 56 psi is -- on the 195's, my spreadsheet says that gives a load rating of 1696 lbs.

I keep at least ~62 psi in my 205's, which, again, according to my spreadsheet, gives me a load rating of 2084 lbs. I have not experienced any noticeable adverse effects from traveling with that much air.

In order to get 2084 lbs on 195's, you'd need to inflate to 65 psi (2094 lbs) if my spreadsheet is correct.

Dave

[greentrail]

Well thanks guys. I apologize if you had posted/published that data table before. If not I guess it's good that my contrasting information got the info out there. I will send that info back to see what they say.

One thing that comes to mind is that they gave me the 55 psi rating for the 205 since the 56 load rating is very close to the number I posted. I will find out and post back.

Thanks again!

[greentrail]

Well Guys,
I contacted them again and the original information that I got was correct and just to double check they verified it with the engineering department. This contrasts with Dave's spreadsheet. Not sure what the reason for the discrepancy is....

Just thought I would pass that on for your info.

[ShrimpBurrito]

Interesting. Well, I don't know how to verify the lower pressures, but the info posted at Tirerack and Kumho's corporate site, the max rating for the 195's is 2094 at 65 psi, which also correlates with my spreadsheet. So that spec on my spreadsheet at least seems to be correct.

http://www.tirerack.com/tires/Spec.jsp?make=Kumho&model=Radial+857&tirePageLocQty=
http://www.kumhousa.com/Tire_SizeChart.aspx?id=7eab87ad-62dc-4d82-897e-e59335de416c

Dave

[Redhawk]

Is there a "top speed" rating for the Kumhos? I know the Marathins are rated at 65MPH, there are times I'd like to go 70 with out worrying about it.

[ShrimpBurrito]

I believe they are Q-rated, which is 99 mph.

Dave

[wmtire]

Is there a "top speed" rating for the Kumhos? I know the Marathins are rated at 65MPH, there are times I'd like to go 70 with out worrying about it.

Really, just about all Special Trailer (ST) tires have a top-rated speed of 65mph. These dual purpose Euro tires, like the Kumhos, are used on vans and other applications and have a higher speed rating.

I checked on Tire Racks website and they said the Kumho 857's have a "Q" speed rating which is around 100mph (if my memory is correct, but I am getting old).

You might want to verify this on Kumho's site, but I saw some incorrect things there the other day...one stating the tire widths were in inches instead of millimeters.

The problem you encounter with webpages, is that the info there is usually put on by a computer programmer/web designer and stuff gets transposed or just entered incorrectly... from what it is supposed to be from the technical/engineering dept.

EDIT: Dave responded as I was typing this. I guess I need to quit being so long-winded. LOL

[larsdennert]

my tires wear in the middle at 60 psi. obvious overinflation for my load.

[greentrail]

Another interesting point...... I asked if lowering pressures have an effect on speed rating he said no. He said that the tire is rated for 106 regardless of what the pressure (as long as it is not overloaded).

[mtnguy]

Is there a "top speed" rating for the Kumhos? I know the Marathins are rated at 65MPH, there are times I'd like to go 70 with out worrying about it.


This is copied from the Goodyear wesite:

Based on industry standards, if tires with the ST designation are used at speeds between 66 and 75 mph, it is necessary to increase the cold inflation pressures by 10 psi above the recommended pressure for the load.

Do not exceed the maximum pressure for the wheel.

If the maximum pressure for the wheel prohibits the increase of air pressure, then the
maximum speed must be restricted to 65 mph.

The cold inflation pressure must not exceed 10 psi beyond the inflation specified for the
maximum load of the tire.

Check out: http://www.goodyear.com/rv/pdf/marathon_gen_info_032806.pdf

I don't do this. There have been occasions where I need to go over 65 mph for a short period to get back into traffic or something, but I really like keeping it under 65 mph......even on WVa. interstate, where the speed limit is 70 mph.