Khumo Tire Pressure
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Team Owner
Joined: May 2004
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From: SoCal
Khumo Tire Pressure
I ran my Goodyear EMT's at the GM recommended 30 psi. I figure this was based on the runflat. My fronts wore perfectly. My rears wore evenly but heavily in the middle.
I now have Khumo MX's.. 265/35 and 295/35 on 18 inch wheels. What do you guys recommend for tire pressure?
Thanks for any imput...
I now have Khumo MX's.. 265/35 and 295/35 on 18 inch wheels. What do you guys recommend for tire pressure?
Thanks for any imput...
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From: King George VA
Non run flat Kumho MX, correct? I run mine at 30-32 psi. I normally go a few psi higher in the front. If I were taking mine on the track, I'd set them at 32 front, 30 rear to start and go from there.
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Instructor
Joined: May 2004
Posts: 138
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From: Dallas TX
I would run 32 psi up front and 30 psi in the rear when the tires are "hot" or at operating temprature. The reason for the higher psi up front is there is more load on the front during breaking, and weight seems to transfer up front more often with the exception of hard acceleration. These numbers are good for the runflat MXs and the non runflat MXs. I just bought the Kumho ESCTA MXs a few days ago. I hope we can get some decent milage out of them.
Le Mans Master
Joined: Sep 1999
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From: Los Angeles CA
Same as stock, 30lbs, adjust up or down to suit your suspension and comfort requirements. However, the Kumhos will show a greater pressure increase at the track, so you may need to let out a little air after the first session.
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Joined: May 2004
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From: SoCal
Originally Posted by allanlaw
Same as stock, 30lbs, adjust up or down to suit your suspension and comfort requirements. However, the Kumhos will show a greater pressure increase at the track, so you may need to let out a little air after the first session.
Ok...looks like no difference than stock EMT pressures. Just thought I would make sure. I would like these to last also. Got 24k on the stock tires. Back were pretty slick in the middle...fronts had good rubber left.
Allan...curious......why would the Kuhmos show greater differential when heated?
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Joined: Aug 2001
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From: King George VA
Originally Posted by Macinamouth
Allan...curious......why would the Kuhmos show greater differential when heated?
But there could be lots of reasons for variance. Some tires have more mass, thus can absorb more heat, which will increase pressure more. It may be that the Kumho, which appears to be a heavier tire than the very thin stock F1, can absorb more heat and thus increase pressure more.
Or..., he may have gotten more water in the tires when they mounted them (lubricating the wheel with the soap mixture). Water will evaporate in the tire as the tire gets hot and this will cause pressure to go up much more than with dry air. It is for this reason that lots of racers use Nitrogen vice air in their tires. I haven't gone to that extreme, but I do bleed my tires after having them mounted and refill from my compressor which has a water separator on it.
There is so much variance for so many reasons that there is no one right answer. Start at 32 front, 30 rear and see how it works for you. Monitor the wear and if the crown starts to wear first, lower the pressure.
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Team Owner
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From: SoCal
Originally Posted by Subdriver
I haven't experienced this with my street Kumho's, but I don't have a lot of experience with them on the track. I also haven't experienced this with the Kumho race V710s.
But there could be lots of reasons for variance. Some tires have more mass, thus can absorb more heat, which will increase pressure more. It may be that the Kumho, which appears to be a heavier tire than the very thin stock F1, can absorb more heat and thus increase pressure more.
Or..., he may have gotten more water in the tires when they mounted them (lubricating the wheel with the soap mixture). Water will evaporate in the tire as the tire gets hot and this will cause pressure to go up much more than with dry air. It is for this reason that lots of racers use Nitrogen vice air in their tires. I haven't gone to that extreme, but I do bleed my tires after having them mounted and refill from my compressor which has a water separator on it.
There is so much variance for so many reasons that there is no one right answer. Start at 32 front, 30 rear and see how it works for you. Monitor the wear and if the crown starts to wear first, lower the pressure.
But there could be lots of reasons for variance. Some tires have more mass, thus can absorb more heat, which will increase pressure more. It may be that the Kumho, which appears to be a heavier tire than the very thin stock F1, can absorb more heat and thus increase pressure more.
Or..., he may have gotten more water in the tires when they mounted them (lubricating the wheel with the soap mixture). Water will evaporate in the tire as the tire gets hot and this will cause pressure to go up much more than with dry air. It is for this reason that lots of racers use Nitrogen vice air in their tires. I haven't gone to that extreme, but I do bleed my tires after having them mounted and refill from my compressor which has a water separator on it.
There is so much variance for so many reasons that there is no one right answer. Start at 32 front, 30 rear and see how it works for you. Monitor the wear and if the crown starts to wear first, lower the pressure.
Interesting:
1. I thought the Kuhmo would be lighter as it is a non runflat!! Thats what I have heard about a million times here.
2. I'm going to have nightmares tonight regarding partial pressure coefficients between different gases from my old chemistry classes
Drifting
Joined: Oct 2003
Posts: 1,884
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From: Walnut CA
I'm sorry I'll be no help with your question but I just wanted to say that its really wierd but I had the exact same thing happen to me where the rear Goodyears both are worn out in the middle and not so much on the edges (the edges are at 3/32" and the middles are at like 1/32")! And I'm running the tires at about 26psi cold... which is right around 30 hot... I don't get it...
Originally Posted by Macinamouth
I ran my Goodyear EMT's at the GM recommended 30 psi. I figure this was based on the runflat. My fronts wore perfectly. My rears wore evenly but heavily in the middle.
I now have Khumo MX's.. 265/35 and 295/35 on 18 inch wheels. What do you guys recommend for tire pressure?
Thanks for any imput...
I now have Khumo MX's.. 265/35 and 295/35 on 18 inch wheels. What do you guys recommend for tire pressure?
Thanks for any imput...
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Le Mans Master
Joined: Sep 1999
Posts: 7,393
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From: Los Angeles CA
Originally Posted by Macinamouth
Allan...curious......why would the Kuhmos show greater differential when heated?