texas008

set of P7 installed on my LS460 yesterday,
first day driving experience as opposed to the old Michelin Pilot Sport AS3 (dry road highway driving, same 35psi cold pressure)

P7, being new tires, have more cushion, comfortable, quiet, but feel a bit more bouncy and less sticky, resulting a bit less confident,
old Michelin, stiffer, louder, very sticky and lots of confidence for dry high speed driving

texas008

all tire work done in Discount Tire, not sure what they use, probably just air,

Dave144239

Regular air is 78% Nitrogen anyway, so that makes zero difference. For more on the Nitrogen scam, see here -

Dave144239

There, fixed it for you The type of gas in your tire has zero effect on road noise or handling. Watch the video for details. Remember, the gas is just a filler that exerts pressure on the tire to keep it inflated.

dlbuckls10

Got a strong cold front and the PSI in all my tires drop about 6 points with nitro.

FatherTo1

While it is true that air is already comprised of majority Nitrogen, Costco fills tires with Nitrogen for free (or they already account for it in the cost of tires) and I do notice less of a pressure drop when I do my monthly checks. I wouldn't pay a separate fee for Nitrogen but my experience has been that pressure seems to stay more consistent longer.

Dave144239

The difference is so small as to be meaningless. From the video, (and yes, you should really watch the video):

Nitrogen size - 300 picometers
Oxygen size - 292 picometers, a difference of 2.7%

Pressure swings with temperature on hot laps:
Nitrogen, pressure changes from 32 psi to 34.096 psi
Air, pressure changes from 32 psi to 34.184 psi

The difference is 0.088 psi, or 0.25%.

Yes, a difference exists, but who would ever notice it?


Pressure loss over time (I believe it was 15 weeks) from Consumer Reports test:
Nitrogen filled lost 0.042 psi/week
Air filled lost 0.067 psi/week

Again, a negligible difference.

FatherTo1

I had the Michelin Pilot Sport AS3+ on our previous LS 430 and drew the same conclusions as you did - stiff and loud. The tires looked great and gave the LS a nice aggressive stance, but those AS3+ tires were the first Michelins that I hated with a passion. They completely ruined the ride of the LS and were so noisy. Adjusting the pressure lower didn't help either. The P7+ is very cushy compared to the AS3+. After 20+ years of buying only Michelins, the AS3+ drove me to the Pirellis (after I learned of the P7+ from the fine folks on the forum).

texas008

it was raining last night and this morning.
The P7 performed pretty well on wet highway in the rain, no slipping @ 80 mph.
where my old Michelin (3/32 tread) would have started slipping at 60 mph.

SW17LS

The P7s are grand touring tires, the Pilot AS3 are ultra high performance tires, so yeah the tires have very different personalities and will be pretty different. Really not comparable tires.

Which is better for your LS depends on you. The car will be much softer and quieter on the P7s (which I prefer), but it will absolutely lose grip and handling confidence over the AS3 or any other UHP tire.

texas008

agree, this morning when taking off from a traffic light, i felt the rear tire spin on the road a little bit, which never happened to the Michelin PS AS3.