[firefish]

Toyo recommends (from memory) between 32 and 38 psi hot for the R888. You out there who are rolling on these, what pressures are you running? I do not mind sacrificing a little bit if grip on public roads to gain more mileage out of the tires so I figure I should be in the higher end towards 38, maybe like 36 cold. I do not think that I'll see anything close to more than the lower running temperature of the R888 on the road anyway so I think it is safe to go quite high even with cold tires. Anyone using nitrogen?

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[flash]

tire pressures are dependent on way too many things to give a spec, regardless of what brand, size or model - the thing to do is to chalk your tires and see what you need - when you get to the point where you are rubbing off all the chalk, you're there

as for road pressures, you'll never get close to rubbing off all the chalk there, so don't even try - they just don't get hot enough - start at 36 all around and see what it feels like and what your wear patterns are - get as close to the edge as you can without going too low on pressure - i would not go below 33 on the street on any 17" tire, and not below 34 on any 18

nitrogen can be a really cool thing for a full on highly competitive RACE CAR, as it limits expansion due to the nature of the gas - however you must realize that air is already 78% nitrogen, so how much benefit you get is dependent on the storage integrity and purity of the supply, the selective permeability of the tire, and the duration of use

it is a complete waste of money on an autocross car or a car that does not have its air changed out each race

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[firefish]

About nitrogen - I have it at work so it is no hazzle for me to fill the tires with it. It is for aircraft use so I suspect it is of the highest purity.

I am not going to chalk my tires. I was simply wondering what the other R888 users where running with in general. But I guess it is better to be on the high side.

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[flash]

actually it is better to be a bit on the low side for grip, but high for fuel economy, albeit at the expense of tire wear

again though, to determine what other guys were running with that tire, you would have to factor in camber angles, spring stiffness, sway bars, yada yada - depending on these things, it could easily change the numbers by 3-4 lbs

the best way to figure it out is to monitor your specific use - a piece of chalk and a hundred miles, and you'll know

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[Fox944]

my Pilot Cups are Nitrogen filled @ 34Psi. 18" Wheels. I'm on the same boat. Get nitro for free at work, so why not. Air pressure doesnt fluctuate nearly as much btwn hot/cold.

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[firefish]

<!--quoteo(post=71291:date=May 3 2009, 09:58 PM:name=Fox944)-->QUOTE (Fox944 @ May 3 2009, 09:58 PM) <{POST_SNAPBACK}><!--quotec-->my Pilot Cups are Nitrogen filled @ 34Psi. 18" Wheels. I'm on the same boat. Get nitro for free at work, so why not. Air pressure doesnt fluctuate nearly as much btwn hot/cold.<!--QuoteEnd--><!--QuoteEEnd-->

Agreed. I actually think it makes just as much sense on a road car as on a track car. The spread in actual operating temperature is just as big, maybe even bigger, in the tires on the road car than on the track car.

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[flash]

it has never been my experience that road use has caused more than about half of the pressure increase seen on the track, regardless of tire type, brand or size

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[firefish]

<!--quoteo(post=71482:date=May 6 2009, 06:26 PM:name=flash)-->QUOTE (flash @ May 6 2009, 06:26 PM) <{POST_SNAPBACK}><!--quotec-->it has never been my experience that road use has caused more than about half of the pressure increase seen on the track, regardless of tire type, brand or size<!--QuoteEnd--><!--QuoteEEnd-->

I was speeking more in terms of big spread in ambient temperature from day to day. I for one am not the type of person who checks and sets the pressure very often. For a track day - yes definately and every time - but not for street driving. Quite stupid of me actually...

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[flash]

not stupid at all - who would think to do that? you're not generally taught to do that - in fact, i think people are only taught to check once a month or so

that being said, i have always checked my tires at least once a week

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[firefish]

<!--quoteo(post=71498:date=May 6 2009, 08:16 PM:name=flash)-->QUOTE (flash @ May 6 2009, 08:16 PM) <{POST_SNAPBACK}><!--quotec-->not stupid at all - who would think to do that? you're not generally taught to do that - in fact, i think people are only taught to check once a month or so

that being said, i have always checked my tires at least once a week<!--QuoteEnd--><!--QuoteEEnd-->

Those wireless pressure monitoring thingies might not be a bad idea after all. Dunno how much they go by in the US but here they charge you like 150 USD for a kit. Even if you do not count in the performance gain by running the correct pressure you'll probably get the money back in tire mileage. Maybe not in one set but perhaps in two.

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[flash]

i have those in the denali - LOVE them - not as accurate as a tire gauge, but very useful, especially when towing, where pressure is critical and it is easy to overload a tire

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[ds968]

On our Pathfinder, Nissan's suggested tire pressure is 26 PSI. Seems way low to me, but maybe because of the higher center of gravity on an SUV, they feel more rubber on the road minimizes the risk of a rollover, a far greater
concern than mileage and tire wear which might suffer a bit at 26 psi [img]style_emoticons/<#EMO_DIR#>/huh.gif[/img]

On the 968 I found my sweet spot at exactly 30PSI all around. Best handling, best coverage ( I did chalk the tires )
in all conditions with that inflation level. I have my ride set exactly in the mid-points of firmness on the front shocks as well as the rear.

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[MC968CS]

I have used many sets of R888's on my 968 CS. I use them for the odd street drive, and mainly for track days. I found for the track just 32psi Hot is excellent on a 968. I run factory pressure hot on the street, as they never get near threshold anyway. Hope that helps.

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