Ya this thread is all over the place. Driving style, being past break-in, gas left in tank between readings, traffic, conditions, and even the undying weight issue may have more effect on gas mileage than 6MT vs 5AT (based on the estimated fuel economy difference between the two). We kind of need a breakdown of all the different aspects.

Also, driver skillz:
Until a car is intelligent enough about the surrounding traffic, it can't use tricks like that on its own.

 

Silke, that's the point though, isn't it? Miles per tank is a function of your mpg, which is a function of driving style, driving conditions, car performance, etc.

You have to look at the mpg, not miles per tank. According to the trip computer right now, I've got 130 miles on the tank and another 329 to go.

I just drove to work at 5:00 am across a heavily patrolled 24 mile bridge with a 65 mph speed limit. The rest of my total 42 mile commute included:

7 miles at 75 mph on an interstate;

5 miles at 60 mph on a state hwy with no signals; and

the remaining 6 miles at 45 mph where I had to stop for two traffic signals.

On the way home, a lot of that will be stop-and-go, so the mileage will drop. I'll still be able to get about 400 miles out of the tank before I fill-up again. When I do that, the gauge will be around an 8th of a tank left. The computer will probably tell me I have 35 - 40 miles left on the tank.

The Nav system "info" page is telling me I average 23.7 mpg. It is climbing a tenth about every other tank of gas. When I eventually switch to Mobil 1, I expect at least another mpg. We'll see.

 

Great info. Yup, personally I prefer to measure mileage by odometer readings and amount of fuel pumped back into the tank, and even then over an average number of readings rather than how far you can go per "tank". However, this thread does quote mileage in various ways including miles per tank.