^Great post Steve. Thanks.

The issues don't really get any worse at 600hp on a 996TT. As a matter of fact it actually gets more reliable since issues like diverter valves have already been resolve at that power level.

You can't even imagine the reliability issues with 600hp Japanese cars (The Supra and GT-R excluded).

Good luck,
Steve

Steve,

I'm curious, how does the maintenance of your 996 compare to your M3 and M5?

Both the M3 and M5 have less of the small problem areas, but they have some high dollar problem areas that easily offset this.

The SMG pump on the M5 cost several thousand dollars if it goes and the VANOS hub on the M3 can fail and take the whole engine out. So, all cars have their problem areas. With that said I have 55,000 trouble free miles on my M5 and 160,000 miles on my M3 with no major issues. I actually do HPDE's in my M3 and I have owned it since it had 11,000 miles, so it's been a great car. I'm sure I'll have it until it dies, or I put an M5 V10 in it.

Don't be afraid of the 911, just get a good one and maintain it.

Later, Steve

Awesome thread! I've pretty much been searching through past threads for this very info. Thanks a lot fellas and keep them coming. I'd love to see cost of some of these repairs as well though

Continuing this thread... how about the issue of RMS (Rear Main Seals)? Does the RMS issue affect the 996tt, or all 996 models? One site mentioned that the RMS issue was resolved in MY2003+. True?

my '03 currently has an rms leak. slow, but very real. it pisses me off greatly.

Usually rms is associated with cars not driven often. It is rare on tt engines.

that wouldn't be me. 102 k miles

Is yours a tt? I assume it is, given your login name....

it is. ..and my 1st one never leaked, gotta fix that.

So I have read a lot of threads about this, but is there proof this even happens? I realize lots of people have thoroughly explained how the AWD system works and have very solid theories how mismatched tires would cause issues, but have these theories on failure ever been linked directly to a failure? I struggle to find any proof.

Viscous diffs in general suck *****, spend some time at a drag strip and that becomes readily apparent. Also plausible, failures here we think are related to mismatched tires could also simply be due to a standard number of failures that will happen regardless. I wonder how many of our front diffs are failed and we don't even know? I'll bet a lot.

There is also the mythical 3% difference variation nobody can confirm or even know where it comes from. To compound the issue further even with perfectly matched tires there are things like thread depth and tire pressure differences which will throw the best matched tires out by more than 3%... Rears wear out twice as fast (or more) than fronts so bald rears and new fronts will be hugely different. There are LOTS of guys who run mismatched tires (look at your next event) and they don't report any problems at all.

IMO, this is plausible but unconfirmed.

i'm not trying to be argumentative, ( or following you as i posted on this topic in reply to you a moment ago, in another thread/time/place ) but it does come from porsche literature. i have read it. now i don't have it handy, so if you again, want "proof" i can't oblige just now. but if i am correct, i am sure it can be found, i just don't feel like searching. but i am sure i have read it, and that i am not fabricating it, or adding to a *myth*. the 3% acceptable range between tire size/differential front/rear for the 996 porsche turbo is factory recommended.