The secret to getting good gas mileage...

... is to drive in the mountains, apparently.

I have tracked my mileage on every tank of gas since I bought my truck last December. Up until a couple of months ago, I got an average of 19.11 mpg on regular unleaded. After I switched to premium, I have averaged 20.06, a modest gain. However, I just got back from a vacation in Colorado, and I was actually surprised by my mileage. Keep in mind this is on a 4x4 DC v6, with about 750 lbs of payload (occupants and cargo).

Wichita - Garden City (1558' gain in elevation) = 18.7 mpg
Garden City - Pueblo (1835' gain in elevation) = 20.2 mpg
Pueblo - Montrose (1033' gain in elevation) = 23.2 mpg
Montrose - Pueblo (1033' loss in elevation) = 25.4 mpg
Pueblo - Dodge City (2132' loss in elevation) = 22.4 mpg
Dodge City - Wichita (1261' loss in elevation) = 20.0 mpg

As you can see, the higher the elevation, the better the mileage that I achieved. Also, each leg on the trip home achieved better mileage than the corresponding leg on the trip out, which obviously makes sense given the altitude changes. I honestly figured that going up the mountains (typically in 3rd gear getting about 5-6 mpg) would wipe out any savings from going back down the other side. The only thing I can think of that helps explain this is simply the engine producing less power (something like 3% per 1000' for a non-turbocharged engine, if I remember correctly), leading to better mileage. The legs that shocked me the most was from Pueblo to Montrose and back to Pueblo, which as you can see gave me a combined average of 24.3 mpg.

 

Was the road new/ smoother? Tail wind? Also, i wonder if wind resistance being lower, higher up is enough to increase efficiency. How much would a tire expand due to lower air pressure, these all sound sarcastic but im not, but im wondering if they actaully add up.

 

I don't remember the any sections of the roads being new. They were mostly average. There really wasn't much, if any, wind while in Colorado. Kansas had wind (as usual), but it was a crosswind the whole time.

 

On a previous truck i would see mpg go up or down and wonder why, couldnt define why. Sometimes i could tell the road surface or wind shift caused it. When i ski you can see well sealed snack bars bulge from the lower pressure, causing me to pop it ith a fork or just rip it a little. A lot of stuff to make the mpg game interesting.

 

Sounds like you drove through Gunnison where I live. I commute back and forth to Crested Butte and average 23 Mpg doing the commute of Hwy driving. I just attributed it to driving 60 MPH the whole time steady on the gas. Get the same MPG everywhere I drive Hwy driving through the state. Just gotta drive mellow........

 

My trips are in the columbia river gorge, windy enough to have an explosion of wind turbines. Other trips go up Mt Hood.

 

Here at home I drive mellow and get 19-20 mpg. As I mentioned in my original post, on vacation I had about 750 lbs of payload, and only had it on cruise during the flat portions. Going up the passes (Monarch and the one just east of Montrose), I was getting 5-6 mpg. In other words, even without driving mellow, my mileage was much higher than I would have expected.

 

I'm seeng 25-26 , I'm on stock tires, but corrected for a slight speedo error. 65 mph for the freeways here

 

Hmmm, with my corolla I got worse gas milage, but that was in southern utah and it was 7500-8000ft elevation. The air is thinner, colder denser air will give you a better combustion thus better mpgs. jmo