[SupraBlur]

I turned 7500 miles recently and decided to try monitoring my fuel economy again. I'm actually pretty pleased; in 50 mile commute in traffic from Glendale to Newport Beach, even only averaging 47mph, I still get 25-26 mpg US. This is specifically trying to maximize fuel economy, mind you, so driving really conservatively. Nice to know it can be done. There are actually stretches where I am over 25 mpg for a long period; they are just cancelled out by stop and go traffic, where I've seen more like 12-15 mpg.

Next time I fill up I'm going to track the entire fuel tank's MPG but I have a feeling with a bit of effort, I can maintain low to mid 20's for an entire tank average. (measured both using the onboard trip measurment, as well as comparing miles travelled versus gallons pumped... they are both in agreement with each other so I'm led to believe it's fairly accurate)

Much better than the 17-19mpg tank average I was getting just a couple of months ago when the engine was less 'broken in'.

 

[Audistic]

Wow... That's really impressive!... And you have aftermarket wheels too... Not sure if this matters but what brand of gas you pump?

What's also interesting for 2009 too is that the 6MT has to pay guzzler tax... The automatics don't.

 

[bb vign]

Here is my fuel economy update (as taken from TrueDelta):

 

[SupraBlur]

Wow... That's really impressive!... And you have aftermarket wheels too... Not sure if this matters but what brand of gas you pump?

91 octane from either Chevron or 76. The slightly different final diameter on the tires probably makes a very slight gearing difference, but since I've been playing around with trying to get max MPG, I noticed that gear and RPM have way less of an impact than one would think.

In fact there are conditions where you would get better gas mileage in a lower gear. Load makes the biggest difference, so there's no higher-gear-is-better general rule; there's always an optimum gear for a given speed -- if you find that sweet spot where the drivetrain is neither accelerating or decelerating the vehicle, you can make over 30 mpg. The trouble is in the real world, you are constantly compensating for varying road elevation, other cars, traffic lights, etc.

What's also interesting for 2009 too is that the 6MT has to pay guzzler tax... The automatics don't.

The automatic is more likely to manage its gearing correctly (per my above observation), so for average driving, it will get better gas mileage. With 6MT we have a tendency to select gears in anticipation of the driving demands (i.e. you probably won't shift any higher than 2nd if you are creeping 20 feet at a time in stop and go traffic, but the automatic will always try to optimize the gear for the speed and load, since it doesn't know you're only going to be dead stop again 3 seconds later).

Here is my fuel economy update (as taken from TrueDelta):

I totally agree with this -- if you have a lead foot, the gas mileage sucks!

 

[EErider]

Thanks for this info...

I should be receiving my S5 (6 speed manual) sometime in March and have been reading about the fuel economy others have acheived. Certainly I wouldn't be buying this car if that were my primary concern but it was bothering me a little bit to think that it wouldn't get as good an mpg as my Tundra 4x4! I kept thinking that the S5 is pushing so much less air than the truck that mpg in the low-mid 20s would make sense. From some review site I found the gear ratios, final drive ratios, etc. and calculating from this data I came up with the engine spinning 2350rpm @ 60mph. Is that the rpm you people with S5s observe?

Thanks!