20100620

Hypermiling Our VW Beetle


Hypermiling Our VW Beetle
Originally uploaded by mikeysklar

Wendy and I took off early this morning destined for the ABQ airport. She had a afternoon flight and I had the onerous job of dropping her at the airport, making a u-turn, and driving for another 2.5 hours back home. This 5 hour (300 mile) airport drop-off is the downside of a living in the middle of nowhere. We have minimized the expense by making our own biodiesel and having a high mileage vehicle. Today I noticed we can further reduce the resource drain by driving really slow! Wendy drove to ABQ going 65 mph averaging about 30 mpg. I drove home going 55 mph and disabled the air conditioner while climbing big hills. My mileage was roughly 60 mpg. I realize there can be many variables here so I'll test the super slow speed thing further when I have to pick her up. Sadly, New Mexico has a 75 mph speed limit on the interstates which means everybody gets lousy mileage if you dutifully follow the posted speed limit.

12 comments:

Artric said...

Good job! I'm interested in seeing what you can get going even slower. The difference between 50-55 and ~65 is big for me. I can get as high as 100MPG at the lower speeds in my Insight.

You still win though, because I have to purchase my gas :).

Keep up the good work!!

Starsquid said...

AC versus open windows showed that there was no appreciable difference in gas savings, as per a Mythbusters episode on the Discovery channel.

Unless you drive with the windows up and no AC, which in the hot weather might be uncomfortable.

I don't know if you pay attention to stuff like Mythbusters because they're not producing exactly science journal quality data, but I thought I'd pass the info along.

Mikey Sklar said...

@starsquid: I saw that mythbusters episode. I am driving with the windows up and non AC while climbing hills. The idea here is not only to drive slow, but reduce fuel usage while climbing hills and increase it while going down hill. The AC has a significant draw off the alternator so rather than breaking in and out of cruise control I just turn the AC on and off.

kristaandjess said...

Nice work! I love hypermiling -- it seems practically magic to just drive a little differently and get free mpgs. It sure is hard for everyone to understand that the speed limit is a maximum, not a minimum!

Ches said...

Wind direction and speed can make a huge difference. I am always looking for flags along the highway to see wind direction. There is sometimes one at a car dealership around Los Lunes and the Walmart in Socorro always has a flag flying. There is a good use for all those flags flying after all.

Mikey C said...

I drive a jeep Cherokee which is not exactly a hyper milers #1 choice of vehicle, but I can back up your findings. The speed limit on Montana highways is 70, and at that speed I'll get about 15 miles per gallon. But when I ease it back down to 60 I get upwards of 19 mpg. That little bit slower speed doesn't really take me any longer to get any where, just a minute or two extra is all usually. And the other upside is that it is a lot more comfortable ride and less bouncy, and there is quite a bit less road noise too.

Urban Turnip said...

I always always drive 55. The speed limit is 65 in some areas in L.A. County, but if I drive 65, I get horrible gas mileage and I have to frequently change lanes and slow down and speed up to get around other vehicles. Going 55 in the right lane, I maintain a consistent speed and I get awesome gas mileage.

Kevin said...

Wow, I'm more than a bit envious of your 60mpg, but I'm a bit confused by Wendy's 30...

I drive an 02 Jetta TDI (entirely too fast) and can usually do 42mpg or so at 65-70mph. In 02, they were using the (now two gens old) ALH engine, and mine is a 4-speed automatic. I looked online a bit, and can't tell if they used that setup in 98...

Something else somewhat related: I find that my performance isn't much influenced by alternator load (because headlights would substantially hurt there), but rather by what setting the AC is on. VW has used "variable displacement" compressors for their AC for some time, and I find that there's a substantial difference between "2" and "3" on the blower knob. I can't say for sure how it impacts economy, but I can certainly feel it in the pedal.

Mikey Sklar said...

Ches: Our dominant wind is S, SW. It was light less than 9mph on my return trip as I was driving directly into it. The wind is definitely a big factor when it picks up, but if anything it should have made my mileage home worse.

Mikey Sklar said...

@kevin: My fuel gauge tends to have a wobble factor, and my home made fuel changes the game. Biodiesel puts me at a 7% energy disadvantage to diesel fuel.

We did have the AC on higher when she was driving (setting# 2, versus number 1 on my way home). We also had a weight drop of 200 pounds once some fuel, Wendy, and he luggage left the vehicle.

My guess right now is that the most significant contribution for mileage is from the engine and air temp both being hot. It was a 100F degree day and I had some great numbers on the way home in full heat after driving for nearly 3 hours (warming up the engine).

Christopher Weeks said...

Do you ever use the pulse and glide technique? It makes a huge difference on our manual Civic and our automatic RAV4, but seems to *decrease* my economy in the automatic Highlander that we just got.

Mikey Sklar said...

@Christopher: I've not tried pulse and glide. I had to look it up. One site mentioned this technique was only applicable to hybrids.