Hey guys,

I wanted to know what everyone else thought about this. I have a 03 with 60k on it. This car does not handle well above 80 or so and I drive 90-95 on the highway. (Don�t flame I drive 1k Miles/wk for work and its on empty interstates) My problem is this car just always wonders and never really settles in at these speeds doesn't feel the most stable. I understand this car will never fell like my M3, but my M3 at 145 feels better than this car at 85. I'm guessing most is b/c bad aerodynamics, but maybe suspension?

I have good tires on it, and it has done it before and after!
My tires are Hankook ultra high perf all season.

I also had the stealer do an alignment and it still is the same!

Also car has never been wrecked, and has always done it.

The G35 loaners I have had from the dealership are the same way, is it possible they all just suck!

On a side note the windshield wipers suck at 80+, any fixes for that?

Thanks for any insight on this!

You are right, there are very few cars that can compare to the M3 at high speeds. My G got much more stable when I dropped in some Eibach springs. Give it a shot. It's a very inexpensive mod.

I agree.. I think with some suspension tuning, wider tires/wheels, it feels much better... Lowering it does help for me as well..

so.. is Eibach the way to go or what about H&R? I have their kit on my other car and I am very happy with those.

I did 120+ and it was fine...

My 03 with the Sport suspension and 350Z/coupe springs feels extremely stable at speeds above 70mph.

As for aerodynamics, the G35 sedan has a CF of a mere 0.27 (0.26 with the rear wing) which is better than most anything on the road, especially your M3 (0.33 CF). The G also has zero lift aerodynamics. These two things greatly increase high speed stability. If you want your G35 to feel like your M3, then you're going to have to add lower profile and wider tires and a much stiffer suspension to match your M3's rather harsh ride quality and immediate handling response. Remember, the G35 is not a factory tuner car like your M3therefore you can't expect it to have the same performance qualities or levels.

To each, his own.
Back when I was an "invincible" idiot I managed to do 145+- at the track on my stock setup. Car handled fine. I've hit 100+ numerous times and the car runs fine although I personally don't feel like anything 85+ is safe for me.
You have to keep in mind that out of the factory, the car was not intended to be driven at such high speeds (despite it's power and ability to do so).
-George

I have an 03 and travel 1K weekly also. While I did not find the car "floaty" over 80 mph, I too added suspension components (shocks, sways, VRT Strut bar). Each addition definitly added to the enjoyment and the stability of the car. The drop probably gave the biggest noticable improvement.

When I dropped my car with 350z/coupe springs I immediatley noticed the car to handle better. Next I will be getting Stillen swaybars installed on the car.

my vehicle handled much better even with a modest 350z drop. i think my excessive neg camb had alot to do with it as well.

Guess it tells you then where I'm coming from that I think the G35 (stock) is the best handling car I've driven at speed so far.

Never driven a M3, though, and the 3 series and TL I've driven has been with a saleman in the passenger seat, and nowhere near that speed

I have 05 sedan and on anything above 60-120mph... its rock solid.... very stable in straight line. If your car is 'wonders off' as you say.... most likely its your tires and not the car itself. Im not a fan of Hankook... and wont recommend them to anyone. I have OEM RSAs right now and once they wear off i will go to Yokohama AVID V4s.... but if you are not talking about cornering.... then of course... its no M3.

I understand this wont hanle like my M3, and I wouldn't want it to. I think I may need to get springs or something like that.

-DaveB said this car had CD=.27 and that is super low, so why does our gas mileage suck? Even when I go 80-82 I get 20mpg and when I go 90-95 I get 19mpg. (and this is all highway) I also just got a tune up,-new air filter,plugs,cleaned MAF, tranny flush, coolant flush, and alignment and none of this helped my mpg.

Thanks for all the great info guys!!!

You try to compare a $30K car with a $55K. No matter how good is the G will never be like the M out of the showroom.

I get about 25 mpg on the highway.... especially if i maintain it right about 80 mph.... if i go faster then mpg drops down.