Been awhile since I've hit these forums - hope everyone and their Gs are doing well.

I'm at 33K mi. on my stock '08 G37S (6MT). Problem-free other than the recent muffler rattle that started a couple hundred miles ago (lasts only for the first minute on cold starts - and actually stops when I put a little pressure on the exhaust tip, so I don't think it's the TSB issue).

Anyway, I was wondering if a few of you more technically-savvy guys would share some thoughts regarding how/when/why higher car mileage begins to affect overall acceleration.... specifically for our cars, and in general. If feels like my coupe isn't as fast as it was during the first 20K miles or so.

I haven't yet done my 30K service (and probably should since all I've ever brought my car in for have been for oil changes). But are there any inspection points done at this 30K service tier that might uncover & address a decrease in acceleration? If not - aside from doing an ecu flash, what other courses of action (diagnostics) might one take to ensure performance is optimal? Again, i'm talking stock levels only.

Would appreciate to hear some gear-head perspectives - and also, anyone with over 25K miles on their Gs who may have noticed similar power/acceleration decreases.

 

Could be the summer heat slowing her down

 

Most cars usually get a bit faster after they get some miles on them. Maybe it just feels slower, but it's really not?

 

the G's not slowing down, you are just getting used to it.

 

Have you checked your engine air filters?

 

There is no reason a car should slow down with age assuming it's maintained properly...
If anything, it should get a little faster (very negligible)

Even if cars did get slower with mileage (which they don't), 30k is nothing... it's still a baby

You may feel it picks up a bit better after some maintenance (filters, clean MAF etc...) but you're likely just getting used to the car

 

Clean those throttle bodies!

 

MIne had 40k when I traded for my 2010 and it didn't feel any slower than when new. I would guess you are just used to it now and it just feels slower. Otherwise, as has been said, check the air filters....

 

Thanks all. Yeah, my hunch was that I've gotten used to the car - no doubt, it's the fastest ride I've ever owned.

I'll check the air filters later.... and regarding cleaning the throttle bodies, maybe it's high time I just throw some nice aftermarket intakes in there while i'm at it. Guess it's a bit pathetic that i've remained bone stock after 2 years...

 

Our cars like cooler weather.

 

Also, at every 30K miles I get a pressurized\time lapse fuel injection service at NTB. It puts that kick back, you definitely feel it and if your tracking MPG you will notice an increase.

 

there was a recall on the exhuast for the 08 models i know this becuase i had the same problem and they switched mine out go before u run out of warrenty or just get a new exhuast system

 

Yea that rattling in the beginning is the exhaust lol.. Have that same problem, getting it fixed on Monday.

But you should try driving a Honda. After 5minutes you will miss the hell out of your G. That's when you get back in it and you love the power just as much as you did when you first test drove the beauty! <3

 

You won't miss the transmission (assuming 6MT)

 

Yeah muffler will just get worse. it will start doing it more. just got mine replaced last week. Finally i can start it without being embarrased