You nailed it... drive like an old blue haired lady and you will see the numbers quoted here. It's a bit silly to compare MPG without comparing the time and speed that it took to achive it.

 

More people NEED to be driving like old ladies and fewer like Jeff Gordon.

 

I think it is dangerous to not keep a constant speed. Trying to save gas by speeding up on downhill grades and creeping up uphill grades will cause a wreck (or at least gestures from other motorists ).

 

I found that just turning the cruise control on at 70 mph, Ac on, and ECO mode on will get me 42.5 mpg highway.

 

Couldn't have said it better myself. I haven't actually looked, but I would guess that the top 10 cars in the mileage database are all from flat-land areas.

 

I don't believe in the whole location thing as much. I live in NJ and these are far from flat lands out here. Learning to be a little bit patient and anticipating traffic plays a much bigger role in increased mpg.

I have tried different experiments on my daily commute of 43 miles to work doing about 70% freeway driving and the rest on 29% large streets (Route 1 South) and very few minor arteries (less than 1%).
These are the results:


I obtain approximately 35 mpg when I drive @ a speed of 90mph on the freeway and complete the trip in 51 minutes.

I obtain approximately 39 mpg when I drive @ 80 mph on the freeway and complete the trip in 55minutes.

However, when I drive at 60mph (actually varying my speed between 60 to 80 mph based on varying elevations) I complete the trip in 1 hour and obtain over 43mpg, sometimes as high as 49mpg.

Patience plays a bigger role.

 

Well I will say one major difference in terms of location--winter. No way can you deny the effect on a full year's driving for having temperatures down below freezing for a few weeks, like I did this Feb. FE dropped down to around 30 mpg for my worst tank, and just a few others in the lower 30s dropped my average for a year down to 35 mpg, despite starting out upper 30s to 40-ish for most of my tanks.

I do think there's an effect of hilly vs flat, but without some serious and exacting study I don't think it's easy to define. And I'm sure it varies a lot by driving style. Up hills is always going to suck more gas than you want, and I'm not sure the downhill coasting compensates for it, so I'd tend to think flat will get better results--but then again my recent mileage, my current tank averaging about 46 mpg nominally (2 commutes to/from work so far) is including at least one fairly major though gradual hill (actually a little hilly stretch that kind of peaks then comes back down), and with a little careful driving it's still possible to keep it in EV mode for a decent chunk and minimize gas. Or I wouldn't be seeing 45+ mpg overall. Both directions.

 

Your reading too much into my posts. Going "fast" down hill is about 68mph, and going "slow" uphill is about 63mph. These speed fluctuations never influence traffic in a negative way. What is dangerous is the aggressiveness of drivers doing 80mph. Also, going 45-50 mph on a road that is parallel to the freeway that I could take is simply doing the speed limit. The additional time spent behind the wheel because of driving more slowly is really minimal. It adds only minutes to the commute and I get great gas mileage. Don't get me wrong, I still have to use the freeway but I avoid it as much as I can. On this particuar tank of 260 miles, 230 are pure highway and I'm getting 49.9mpg so far. If going the speed limit, or a few miles under, is considered being a "blue hair" then I guess I'm one.

 

I have become convinced that location does have a major affect on mileage. I was in southwest Florida all winter (Sept. till May) and my fuel average was 37 or so. Since returning to RI for the Summer I am now averaging 44 to 45 mpg. I'm now driving mostly on two lane secondary roads and going into electric mode quite often. In Florida, although it was much flatter than here, my average speed was a lot higher and I think that accounts for the difference.

 

Not True! Number 6 in the data base, (at least, today) lives in the mountains in NW Washington. My home is 2800 feet above my work, and the car is used mostly for commuting the 34 mile distance. I have pretty significant foothills, the largest of which is 600 feet, to climb every day. Not surprisingly, I find my mileage suffers going home, but is significantly better going to work. The speed is about the same both ways, 55-60 on a two lane mountain road with lots of curves but no tight hairpins. I spend most of this driving time attempting to keep the car in either glide (Hard to do on a TCH, but possible), coast either regenerating or with EV driving at near idle to maintain speed or the heretical mode.

Once off of the mountain my drive is a series of undulating small hills. Here I try to maintain the heretical mode as much as possible by anticipating the demands for power or for reductions in power with very small accelerator changes, and also I accept small speed changes so long as they are consistent with traffic. This usually means keeping a slightly greater following distance to permit the speed fluctuations, which is safer anyway.

I do have the advantage of rarely requiring AC and of generally cool temperatures of 60-80 in the summer months, and 35-45 in the winter.