2008 G35X - love it but the gas mileage not great always using premium. Getting 19.2 mostly city with some highway per the mpg calculation above the odometer and that has seemed right per fill ups and miles. Occasionally take a long highway ride, typically got between 20 and 25 on the bar graph in the center console, about 23 mpg cruising 70 mph for an hour after resetting. Today both ways on a 100 mile drive in minimal traffic cruising 70 mph got between 25 and 30 on the bar graph, about 27 mph. Only differences compared to every other time is switching from dealer's synthetic blend (likely virtually all conventional) to Mobil 1 5W30 and switching from OE Goodyear Eagle RS-A's to Michelin MXM4 Primacy tires both in the past 2,000 miles. Could one or both of these made this difference? Would love to be getting 27 highway and maybe better all around. Got to start tracking fill up averages.

 

If you want 27mpg, you got the wrong car. you would see that if your driving very long distant and cursing.

 

^ like he said, getting anything near 27mpg for the full tank during normal city/highway mix driving is near impossible (unless you are cruising on the hwy all the time with very little city), changing to a better oil and tires will always help improve your mpgs by maybe 1-3mpg max until they too start to wear out.

 

You guys need to reread what he is stating. He said he got new tires and new oil already, and that he got 27mpg last time he drove on the highway. He is asking which do you think contributed most to the better gas mileage. I honestly do not have an answer for you but I am sure someone here could help...

 

Both, the oil and the tires probably improved the efficiency of the vehicle. A lower friction high quality oil like M1 will improve the efficiency of the internal engine components. Newer lower resistance tires will increase the efficiency of the vehicle by reducing the resistance between tires and the road. On top of that the Michelin's probably weigh less than his Goodyear's, which also contributs to the efficiency of the vehicle. He can also replace the air filters and spark plugs, and increase the pressure in his tires in order to maximize his efficiency.

By the way I own a 07 G35x and I average about between 21 and 22 mpg with mostly highway miles, however most of these miles are spent in rush hour traffic. The best that I ever got was 24mpg from fill up to fill up. Seeing 27mpg for the G sounds to good to be true.

 

I did a few test and the best gas mileage I got was 28+mpg. I just switched to G-oil (green oil) and got even better gas mileage.

 

wow only 18.8 here, with firehawk GT tires (staggered), but with 6mt, I can't help but to rev it up just driving around town, I can't help myself!

 

Bottom line. Once you start paying attention to your driving habits and the desire for for good mileage alters those habits, your mileage will go up.

 

make sure your Air filters are clean as well. Transmission oil change and Differential front and rear since you are AWD. might help as well with cleaner oil.

 

As an experiment, try to take the same trip but instead of putting the gear in "D", go into manual mode "M". Do not touch the shift ****/paddle shifter when you come to a stop (the car downshifts for you at the lowest RPM possible), but when you accelerate, try to shift up as soon as possible (by repeatedly shifting up until the gear changes at the lowest possible RPM, which is around 2000RPM, as you step on the gas gently).

You might get a slightly better MPG because in "D" the car is not intelligent enough hence does not shift up at the the lowest possible RPM.

Also, try to take a different route, MPGs also depend on topography but make sure that it is the same (or even better, shorter) distance to your destination. Preferably, more downhills than uphills and less traffic.

Another tip: drive in the morning or at night, when there is less traffic (no cars to distract you) so that you can concentrate more on your hypermiling skills and techniques.

Before your trips:

- slightly overinflate your tires than normally recommended, just a touch (less rolling friction)
- run on less than a half gas tank if possible (lighter car)
- dump unnecessary luggage/weight, but keep your spare tire

I got 30 MPG once but that's because I took a different route and the back roads are hilly.

 

Going down hill doesn't count. lol

If you want to see 27mpg, should have gotton a civic. Who drives these car for the MPG? I know i don't and i still pray to see 20mpg which i don't get.

 

Maybe you should reread my answer...

I stated that changing to a more efficient oil AND tires, both help with MPGs, so what the OP is experiencing is due to those changes...

 

Want higher gas mileage? Try to drive like this:
- Cruise on highway at 64mph (2600rpm) no more no less!
- In the city, lift up your foot as much as possible to get the car going, never hard accelerate at the stop and go.
Result: you will get 24mpg or more with mix City/Highway.

From my experience, I am now getting 23mpg with 50/50 for the current 900miles.

 

I hate to say it but we drive luxury sport cars. Who babies the sport car. When ever i do drive from LA to SD and back i might drive a little nicer but for the most part, i am pretty hard on my car. I really don't care if i get less then 20mpg. If i cared i would have gotten a yaris. Why would you want to get 27mpg in a sports car?

 

Right now I have averaging 19.9. That was with taking 3 friends for a spirited little jaunt down the freeway 2 days ago. When I am by myself doing 75-80 my car will get anywhere from 25.5 to 29.5. My car does fairly well on gas when im not into it.

I will say one thing though, I was able to baby my 05 a lot better than this car because it was an auto. The 6MT is way more enticing to get the revs up.