My average is 19 mpg, maximum 23 mpg, minimum 16 mpg.

 

I think very unlikely. I think possibly due to uneven fill-up levels. On a recent highway trip, I got 21-22 and was ecstatic.

 

That looks like too much short shifting for our engines

I don't shift before 6k unless my wife is in the car, at which point it drops to 5k minumum shift point if I am trying to take it easy on her, which isn't all the time. Solo, my normal shift is 7k, with ~1/3rd of my shifts at redline. Forget the 'daily'. Literally 1/3rd is at redline. I also tend to sit in a low gear for extended periods through traffic for the much more dramatic speed changes that are available with just minor gas pedal adjustments. I rev-match downshift >90% of the time I need to reduce speed, including dropping it into 3rd from 6th at 70-80, and then back to 6th when I match the speed ahead.

50/50 city/highway.

This method nets me around 20mpg on average, all highway goes up to 23mpg. Lowest I have ever seen was 17mpg. Normal low is 18mpg.


There are alot of factors in gas mileage, and for most cars it is driving style. I disagree for the 8. I think hard driving improves mileage during non-hard driving, by keeping the engine healthy. The health of your ignition system, the compression you are running at, and the condition/quality of your oils (engine, transmission, and diff) are the biggest components of gas mileage for us. Followed closely by fuel content/quality (pure vs E10, additives, etc...)

 

Based on what I've seen with my own ScangaugeII, I think it's quite plausible, depending on what speed he averaged and how long, if at all, he was idling.

Idling at traffic lights screws it, and above 48mph or so, I don't think it's feasible, at least not in my RX-8; but if I was on a road that was long enough, without traffic lights, and all I could do was 45mph (let's say there's a police convention going on in the area for sake of argument), then I'm pretty sure I'd also see 30mpg or better on that specific trip.

My typical trip numbers are 16-21mpg, depending on how long the trip is, how many lights I get stopped and how long they are red, the weather, etc.