aggie57

Better it does it in the parking lot than on the track

TheEngineer

For those who are experiencing this for the first time in northern climates, you might want to put winter tires on the car. They are much safer below 40 F and also greatly reduce the acorn problem - presumably due to the softer compound.

NoGaBiker

Actually, it's not normal for a 911 to do that. At least not on any of the 911 Carreras and Turbos I've owned in the past. It must be "perfectly normal for the wide tires on a 991" to skip in slow speed turns. Because if freaked me out too when it first started happening. Had I been new to 911s I might not have been so puzzled by it, but coming from most recently a Turbo with 19s with summer 305s and 245s I had already experienced these same size tires but never felt anything like this. I actually swung by the dealer to ask about it.

Whatever the explanation, it's stupid as hell. We can make excuses for Porsche all we want, but they've been making 911s with this size Max Performance front tires for decades and suddenly they can't figure this out?

Noah Fect

This is a bit of a pet peeve of mine as well. It happens because magazine comparison tests these days are won and lost by tire manufacturers, not auto manufacturers. Automakers have gone way overboard lately, specifying tires with the goal of beating everybody else around the Nurburgring that don't work as well once someone actually buys the car and tries to drive it on real-world streets.

Look at all the dire warnings in various threads about what will happen if you dare to drive a "high-performance" tire at temperatures below 40F, for example. Some of these rubber compounds are damaged merely by exposure to winter weather conditions in many parts of the US, as some C7 buyers learned. No big deal, though, just "remove your tires and store them" if your garage falls below 20F.

The whole thing is just stupid, and will eventually become genuinely hazardous. But nobody can afford to be the first to stop pushing tire development in this direction... at least not until they end up on 60 Minutes.

aman

Everyone, thanks for the input and sorry for the repetitive post. I did a google search before posting but it did not turn up anything. Now I can rest easy, enjoy the car and hopefully not get too many speeding tickets!!!

Grunty

The acorn noise seems to be partially attributable to the rubber getting hard as the temperature drops. This would suggest that traction is really poor since the rubber is hard. No speeding for you until it warms up again!

PatrickC23

Love the fact that forums like this exist - experienced the Acorn Effect yesterday for the first time given the cold temps. It is not subtle to say the least. Glad I was able to turn to my wife and say "It's normal, the guys on the forum said so."

And yes STG, I will be enrolling as a member soon.

plenum

Or, switch to a different compound tire. Perhaps ALL tires on the 991 will do this at some temp/surface scenario, but I found that simply switching-over to snow tires (Alpin) in colder temps eliminates this annoying trait. I only have this problem in other words when the ambient temp is 40 F or below with my OE Pirelli's mounted.

Archimedes

Meh, I get this on both of my Porsches and my RS5 in slow, sharp turns in anything under 60 degrees. No big deal. Don't know why people freak about it. I just try not to turn really sharply like that unless its absolutely necessary.

911sccab

If you drive on 2 wheels it usually goes away.

Larry Cable

wheelies?

911sccab

I was thinking the left two or right two... get 'em up on edge and they quit cracklin'.

GSIRM3

I had three previous 997's, two 997.1 and one 997.2, and all three did it.

todd92

Just about any car with summer performance tires will do it when it is cold enough.

jimbo1111

It may not be just the tires as most are suggesting. As temps drop the oil in the LSD may be causing unusual lockup of the LSD unit. That is what it feels like to me. I haven't experienced it in my car yet but It happen when I was driving a 991s PDK car last year.