You can get great gs milege out of these cars if they are properly tuned and taken care of. I have a Z-Tube and K&N

 

Agreed, there are definitely lighter tires that those RE050's (actually 27 lbs. in stock size), the new Michelin PSS are also 22lbs.and available in stock sizing, but $$$$

Since I will be looking for tires soon, I'm curious though, did you really mean 225/40 ?? (The diameter of the Conti 225/40 is more than 3% shorter than stock, and it appears they don't make them in the stock size 225/45) If so, what tires are you running on the rears to match that odd size? I'm concerned about VDC issues.

Anyway, that's some great highway mileage you're getting there.

 

Wow I don't no what button I pressed but it posted that reply before I was done? lol
What I was saying is that you can get very good milege out of these care when properly tuned and taken care of. I have a 2007 A/T and I average from 28-32 hwy at 65mph using the cruise control. I got 32mpg for the first time after changing my oil (mobil 1 5w30 synthetic) and gear oil (moble 1 75w90 synthetic). Before then my best was 31mpg. The numbers are accurate because I have a computer programmer the stays plugged into the diagnostic port and reads all my parameters. I drove to a town called Alexandria which is about 38-40 mile away and I used 1.1 gallons of fuel. Im changing my transmission fluid next week and maybe I can get another mpg out of it? We will see? My car came with NGK platinum plugs so I don't have to worry about them until 100.000 miles.

 

i forget that the gas is 4+...and i put the pedal to the metal..
but 1 time i got 29.4 driving to san francisco

 

I feel your pain because im paying $4.19 for premium. But I work 3 miles from my job and I fill up every 2 weeks with a quarter of a tank left if I don't do alot of traveling. I just can't allow myself to put 87 or 89 octane in my car even though my programmer has a 87 tune. The car just doesn't run the same and the gas milege drops. I have always believed in changing my oil and fluids on time and using the best gasoline possible. For that reason I have never had any engine or fuel pump problems in any of my many cars. When I trade in or sale a vehicle you can bet your life that it's been well taken care of so forget the car fax lol.

 

I put my car into the test of the 29mpg myth this afternoon and here is the results.

Length: about 30 miles on highway from exit to exit.
Speed: cruising at 62-63mph (2600rpm, I drive by RPM)
Test object: 07 G35 bone stock except for functional front vents (drilled vents)
Wheels and tires: sport 18" with 245/45/18 rear and 235/40/18 front. All tires are pumped to 45psi.
Extra information: 10-30W synthetic engine oil, new Nissan Matic-S transmission oil, new synthetic power steering fluid. 91 octane gas.

Test 1
- Condition: wet road with light rain.
- Temperature: 61F
- Gas mileage: 26.9mpg

Test 2
- Condition: dry road
- Temperature: 65F
- Gas mileage: 30.5mpg

=> average gas mileage = 28.7mpg

Conclusion: so the myth is CONFIRMED!
I myself never believed that G35s can make do over 25mpg on highway since EPA numbers are 22-24mpg. I would not believe it can do this good until I tested it myself. I don't know about other people but to me, anything over 25mpg is marvelously good on these cars. I will do one more test next week on the same highway with lower speed/rpm, desirably 2400rpm.

 

SO how did you measure these results?

 

By the display on the gauge.

 

i just got this car and i drive about 60 miles highway a day and the most i can get is like 24mpg..and i cruise at 60-65. I do a little bit of driving around town but still lol

 

You should! This will fit your budget and your lifestyle. Stay green.

 

The last gear on the 5AT really needs to be taller, the RPM is so high during highway cruise.

 

That's really good phalanx, I use mobile 1 5w30 full synthetic motor oil, mobile 1 synthetic 75w90 gear oil and for the time being I still have the nissan matic-J transmission fluid but I will be switching to castrol matic-J next week when I change my transmission fluid. At 65mph im running about 2000-2200rpm in my coupe. My vehicles weight is 3540 pnds according to the scale.

 

x2....3000 RPMS cruising at what 72-73?

I try to keep it under 3,000 and thats right around 70

 

I have 5A/T so the rpm is higher than the other new 09-10 model with 7A/T. People with 7A/T, can you share your gas mileage?

 

WOW! I only dream of get 20mpg on the freeway.