Dunlop SportMaxx RFT vs. Michelin Latitude HP

[Texas5]

What air pressure are you guys running w/ your Michelins?

I'm running about 38 cold PSI all around and the ride is pretty firm, but I figure it handles a little better and improves MPG.

[art4.8i]

Originally Posted by Texas5

What air pressure are you guys running w/ your Michelins?

I'm running about 38 cold PSI all around and the ride is pretty firm, but I figure it handles a little better and improves MPG.

i just deflated mine to about 38psi hot all around; they were 45 when I left the dealer. It is now even more comfortable.

[Hans_ACS]

Great write-up ! I wish Michelin would have 21inch tires aswell. I ordered new dunlops (the non-runflat version), but even after 7 weeks of waiting, they did not arrive.

[art4.8i]

Originally Posted by art4.8i

i just deflated mine to about 38psi hot all around; they were 45 when I left the dealer. It is now even more comfortable.

Correction, I run them at 35 psi all around. It would be nice to hear what other people are running on their michelins! thanks

[SpeedR]

Originally Posted by Texas5

What air pressure are you guys running w/ your Michelins?

I run the recommend pressure listed on the placecard on the inside of the driver's door, 32 PSI cold.

For those listing higher pressures on this thread, unless you are hauling heavy loads or driving 100+ for extended periods, why are you running higher than recommend pressure?

[Penguin]

> The cornering with the Michelins is not quite as crisp as with the Dunlops.

Runflats have a stiffer sidewall, so many people find that to get the same handling, they must increase the tire pressure over that of the OEM runflats. You might try increasing the tire pressure and see if it makes a difference.

[SpeedR]

Originally Posted by Penguin

> The cornering with the Michelins is not quite as crisp as with the Dunlops.

Runflats have a stiffer sidewall, so many people find that to get the same handling, they must increase the tire pressure over that of the OEM runflats. You might try increasing the tire pressure and see if it makes a difference.

You are correct, when it comes to handling, the OEM runflats perform better than the Michelins. But increasing your tire pressure will NOT improve handling. It will change the feel making the cornering "feel" crisper, but traction will be less leading to slightly increased chance of under/over steer. Increased pressures over recommended will also wear the centers of your tires quicker.

When most people run their street cars with street tires on the track, they decrese the tire pressure from recommended. For instance, I decrease mine 3 PSI on my M3.

The only time you should stray from the OEM recommend pressures is when you change tire size. Here the general rule of thumb is larger tires require less PSI.

[Penguin]

> The only time you should stray from the OEM recommend pressures is when you change tire size.

To each his own, but be aware that the Technical Editor of Road & Track diasgrees:

"Typically the vehicle manufacturer’s pressure recommendations are biased a bit more toward ride than tire longevity or what most enthusiasts enjoy. More spirited driving often calls for slightly higher tire pressures. As you found out, this makes for more responsive steering and a firmer ride. Go too high and the ride deteriorates, the tire’s contact patch is reduced and traction suffers.

On automobile tires, the maximum inflation figure molded into the tire’s sidewall is the maximum safe cold tire pressure. You obviously should not exceed it, and many times you won’t even want to come close to it due to ride and handling concerns. It’s simply the highest tire pressure the tire can physically withstand, not a recommended inflation pressure."

[SpeedR]

Originally Posted by Penguin

Typically the vehicle manufacturer’s pressure recommendations are biased a bit more toward ride than tire longevity or what most enthusiasts enjoy.

I agree in general, but BMW is not a typical manufacturer. BMW can never be accused of a bias towards soft ride and tire longevity - LOL. If we were talking about a Lexus, it might be a different story.

One last point on tire pressure. The recommend pressures on the inside door frame are calculated for a vehicle at it's gross weight (full load of passengers and cargo). So if you, like I, drive mostly with just a couple of people in your X, your tire pressure is already slightly higher than needed.

IMHO, the bottom line is, run the pressure that feels right to you, as long as it's not lower than OEM recommended and never higher than the tire's max side wall rating.

[Penguin]

BMW has been becoming more of a luxury car manufacturer and less of an auto enthusiasts car for quite a few years now.

I would not be surprised at all if they had recommended pressures a couple of pounds lower to give a softer ride, particularly when one is talking about an X5, as compared to an M3.