Hey guys, I am extremely frustrated. I am getting 6-9 mpg on my 07 G35x (was 6 until I changed my oil to fully synthetic...now getting 9ish) in all city driving. My all highway driving I get 20-21 mpg. I am sure I measured this correctly and more than once. I would check my city mileage after driving around in Scranton for a few weeks, then I would start from full tank when I go to Philly and check it once I get there to see what my all highway mileage.

Anyway, the most frustrating of this:
I called Infiniti to schedule a service appt to see if there's something wrong, and they told me that, while this does not sound normal, if they hook up my car to the computer and it finds nothing wrong, they have nothing to fix. Not only that, but they will charge me $63! What the hell? My car is under warranty and I should not be charged for a legitimate service request. This sounds like a system against getting customers to bring in their cars when they have concerns. Moreover, why should I get charged $63 if they fail to find something wrong with my car, that is getting 6-9 mpg (pretty obviously not normal since it is not a Bugatti). I mean...I am getting the shaft if they find nothing wrong with it, and I am doubly getting the shaft if they charge me.

I refuse to believe the computer can diagnose every problem that may lead to low gas mileage. After all, if the computer knows all, why the hell do we need good mechanics? Any suggestions as to what I should do?
DOMO

 

Go to a different dealer..... thats a bunch of crap. any concern on gas mileage is a mechanical issue and should be covered under warranty. you may want to check your tire pressure, air filters etc too. do you drive real aggressive around town?

 

wow that is low. i get 13-14 city highway 15. but thats about it.

 

They said if they find something wrong, it will be covered under warranty, but if nothing is found, I will be charged. I called another dealer and they said that's the policy.

My pressure is good. I don't know how to check my air filter (is there a DIY somewhere?), but I had my oil and filter changed very recently. I wonder if there is any way to check if the fuel injection system is dirty?

It's weird that I'm getting OK highway mileage (20-21) but such crappy city mileage. I don't drive very aggressively around town (it's kinda hard to do that in Scranton as opposed to Philly)...but there is quite a bit of stop and go (stop signs every block around my house until I get to some normalish roads) and it is also relatively hilly. But not bad enough that my mileage would be that low .

 

I would go to the dealer manager or higher, that's not right!

 

How do you drive? Although 6-9 sounds ridiculous, i'll venture to guess that it's not hard to do that with pretty aggressive driving, in town, with an X. I used to get 12mpg of pure city driving, somewhat aggressive, on my Maxima, and easily get 30mpg on the highway. I can't compare to my G since most of my driving nowadays are on the highway.

As for the fee, it's standard practice. Your car is under warranty, but for issues that are there that can be covered. Diagnostics aren't usually free. However, most dealerships will waive the fee if they do find a problem that's covered under warranty.

Try taking it to a third party, a lot of them will do a basic diagnosis for free although not all can dive deep into the system to check for everything mainly since the CONSULT tool is a fairly expensive investment for small shops who cater to different vehicles.

 

Also, check your exhaust. When i got my G (used), i was getting fairly bad mileage, turned out to be a damaged exhaust.

 

As others have asked, how are you driving it? If you're beating on it, it'll "reward" you with bad gas mileage.

I DD my car, with a lot of stop and go traffic. When I used to drive in DS in predominately manual mode, my mileage was terrible (around 10'ish). To see if there was anything wrong, I tried driving in D mode for 2 full tanks worth of gas to check the mileage. Driving in D, I can get about 15'ish.

Try driving in D, and not killing the pedal. If that doesn't work, get the car checked.

 

Take the twelve dead strippers out of the trunk!

Seriously, a lot of this does have to do with the driver. Most of it is driving style but some of it comes from places you would consider until it's pointed out. How hard you hit the pedal when starting at each traffic light, how often you fluctuate the pressure on the pedal while you are driving, whether you coast to a stop of hard brake just before you get to the next stop. City driving can destroy MPG rates very quickly.
My wife drives her 06 MDX and gets 21 MPG. I drive it and get 25. I drives her crazy but I see what she is doing to cause the drop.

You may have a specific case... I'm not doubting that. There are other things to consider though, so Infiniti does have to be cautious before taking full responsibility for your specific car's efficiency. The driver adds a lot of variables that they have no control of.

 

I don't have an S so I can only drive in D (if that's what you mean)--and I don't put it into manual almost ever.

 

I don't drive very aggressively around town (it's kinda hard to do that in Scranton as opposed to Philly)...but there is quite a bit of stop and go (stop signs every block around my house until I get to some normalish roads) and it is also relatively hilly. But not bad enough that my mileage would be that low .



I do understand that Infiniti should be cautious, but I think that the fact that I am under warranty should guarantee that if I bring my car in for a legitimate concern, any and all fees unrelated to wear items (tires, brakes, etc) should be charged to the warranty.

 

I agree that the very least they could do is scan the computer for free. That's complete BS and a lack of customer support. It takes all of 15 minutes and they're not loosing a mortgage payment by cutting you slack on a $63- bill. They probably made that in profit after hitting you with the bill for the full synthetic oil change.
I doubt they find anything from the scan though....

I have seen a few (not too many) people complain about city driving and severely low MPG but I always chaulked it up to being what it is, a gas hog in tough driving conditions.

I hope they help you out and you find a solution.
Keep us posted.

 

Def get that looked into. That is not right gas mileage by any stretch, even if you were drag racing from one stop light to the next.

 

What kind of dealer charges to evaluate a problem under warranty?!?! That is almost unheard of. I would call Infiniti corporate for their take on this. I have brought my car several times to have it checked out. 3 of those times, they failed to find out why my battery keeps dying. Never a charge for evaluation.

 

Something is very wrong, getting 6-9 mpg city. I agree with Dr Gee; you'd have to be drag racing, uphill into strong headwind to achieve that.
Your dealers sound like scammers.
I have had my brakes fixed under warranty and the dealer didn't say anything like, "well, if we don't find anything wrong with them then we will have to charge you for looking at them". It's ridiculous.
If they insist and you have nowhere else to get it properly diagnosed, then bite the bullet, pay the fee and hope you get it ($) back. In the mean time you are spending nearly double, what you should, on fuel.
Good luck.