City vs. Highway definition
 

Are rural roads considered to be Highway? I get much different mileage on rural roads with speed limits between 35-50 mph compared to what I get on actual multi-lane highways with limits between 50-65 mph. It seems bizarre to classify them together. For example, rte. 110 is a rural road with one lane in each direction that has a stretch of 4-5 mi. without a single stop sign or light. Is that a highway or city street?

I'd call it a highway. Basically 'city' means stop&go traffic, lots of idling, and 30mph or under.

Every user can define it how they like, but if you want the data to be useful, just be consistent with how you describe it between all your fuel ups.

I call any non-freeway travel "city" myself. So if the speed limits are below 55mph, then I call that city, no matter if it is rural or not.

Two opposing opinions ... :-)

I wonder how the EPA defines the terms?

Decided to google it ... up to 2007, the EPA tested city as " ... starting with a cold engine and making 23 stops over a period of 31 minutes for an average speed of 20 mph (32 km/h) and with a top speed of 56 mph (90 km/h)." The highway test "uses a warmed-up engine and makes no stops, averaging 48 mph (77 km/h) with a top speed of 60 mph (97 km/h) over a 10-mile (16 km) distance". So the latter matches my description of Rte. 110.

In 2008, they added some new tests to try and get a more realistic measure, but still, rural roads without stops seem to qualify as highway.

I look at highway speeds as those where the transmission is able to run in its highest gear for more than a mile (or kilometer). You are going to get your best mpg on most vehicles at 45-65 (70-100k). MPG only goes down as you go faster, and driving less than 45 on many vehicles causes (on many automatic transmissions) the transmission to shift down and up too often.

I achieve my best results between 50-60, once the transmission has achieved overdrive and lockup.

But each individual experience may vary. The percentage can be calculated two different ways:

Percentage of mileage driven at city or highway, or percentage of fuel used while driving city or highway. Problem is, for nearly all of us its a guesstimate. Unless you were tracking what distance you actually drove on each, there is no accurate way to know for sure.

I live in the hills of WV which I consider to be VERY rural. The speed limit on most of the roads around here is 55 MPH and I usually drive around 60. But what I have to put up with are very twisty roads where at one moment 60+ MPH is absolutely no problem and then the next you are faced with a 25 MPH hairpin and this is how it goes for almost anywhere we need to go. Given this, is it city or highway?

I'd call that highway.