My personal conclusion on the mileage that I get. Your results may vary. It depends more on the number of discrete trips (start/warm-up/run/shut-down) taken than the speed driven. I just had my best and worst tanks back to back.

Just under 23 mpg with 3 discrete trips which included two highway runs with 20+ minutes of rush hour bumper to bumper; a test drive for a friend including multiple 9k run-ups; and cruising between 80 and 95 mph.

Just under 14 mpg with 9 discrete trips, no 9k run-ups and no cruising speeds over 55mph.

Want better mileage, keep it running.

 

Thanks for the input everyone!

Some of the suggestions are just common sense, which I'd like to think I have a decent amount of. The tire pressure is good. I do vary the gas I use. I have averaged my MPG over several weeks. I am now over 6500 miles and I still am getting only around 10 MPG.

I've kept the pressure on my local dealership's service department and they have asked me to bring my car back in next Wednesday so they can go over it thoroughly once more. They also said they might be contacting the regional Mazda rep to discuss the issue.

I don't intend to settle for 10 MPG even though I love the car. One way or another I will find a way to get closer to the claimed MPG, even if it means buying another 8. Yes, I love the car that much. So please don't suggest that I'm just whining. I'd just like to have an 8 that is running as best as it can, if my MPG are this low, then I feel there must be something wrong with it.

Thanks again!

 

It doesn't take an act of congress to get the regional rep involved. I don't understand their hesitation. They've pissed around with your car long enough. Time to get out the BIG guns! (Who's paying for all that gas?)

 

Ahh, another data collector I have all of the above, plus loan and insurance costs for a total yearly cost and total cost per mile. My best is 20.9 MPG and worst is 15.7 with a average of 17.7 MPG : 4527 total miles mostly city driving.

 

I found your thread quite interesting, because I too get approximately 9-11 MPG typically. I have attributed it to my driving habits (my commute is through LA/BH city streets where I am varying btw 30-60 in second gear most of the time). Personally, I couldn't care less about the mileage from a cost perspective, I drive my 8 less than 100 miles a week most of the time, but if it's some sort of maintenance/mechanical issue I would want to nip it in the bud before it becomes something serious.

However, unlike your experience, I drove to Palm Springs a while back, averaging 75-85 on the freeway and got more like 25mpg...

 

Someone here got 13 mpg consistently no matter how he drove.

Then he switched from 93 octane to 87 gas and suddenly got 20 mpg.

Did you check your tire pressure?

 

Tire pressure could also be contributing to the problem.

 

You are doing the right thing about being on Mazda's *** about this. 9-11mpg consistently means something is wrong somewhere.

 

The manual says 87 octane is okay. That was written by Mazda. If you're ready to get a new 8 over this issue, might as well try it.