100+ hypermiling / ecodriving tips & tactics

[redpoint5]

Originally Posted by PaleMelanesian

You can see where I stand by reading my mileage log. My average fill for the last year is 11.3 gallons, in an 11.9 gallon tank.

Apologies for sounding like I was arguing against you personally. I just quoted your post as a way to introduce my argument, which was directed at nobody in particular.

[PaleMelanesian]

Understood. No problem.

[undata]

Originally Posted by awillard69

Nice, detailed list. It's nice to see it all in one place.

I have a comment regarding #86 and #89, referring to the A/C.

In my experience, the average person thinks the A/C has to be on max blower and max cold. Under those conditions, it's adding maximum load.

I typically turn on the A/C once I'm cruising, not while starting out or in tight traffic. Once it cools down enough to be effective, I adjust down the temp to a more moderate level, something less than max cold.

At highway speeds, my A/C can create frost bite. So, I back it down and while it will still run, it will run less often but still provide cooling - much like your manual cycling, but more "hands free."

I think if you "adjust the temp" the system merely adds engine heating into the mix. So you are going to have to do this by turning the a/c on and off. Be aware that every time you shut off you should leave it off for about 5 mins to avoid damage to the compressor. Likewise, you should shut off the a/c and put the air on recirculate when close to your destination. You will find there is usually quite a bit of cooling left in the system after it is shut off.

[undata]

Originally Posted by BBsGarage

I'm really missing the point of this one.

61) Parking tactics: orbit to bleed momentum

If you find you have too much momentum after reaching your preferred parking spot, continue coasting further down the row or "orbiting" a spot until you can roll to a stop in position without touching the brakes. (Depending on traffic in the lot, obviously.)

Anytime you grind to a halt you convert momentum to heat. A lot of these suggestions apply to cars equipped with a manual transmission. If everything is clear you can coast in neutral and shut the engine off as soon as you know you will "make it." So finding a straight-ahead (ideally pull through) spot can actually save energy as opposed to applying brakes and whipping the steering wheel around. Even though the running time may be slightly longer while "orbiting."

[Legend_Master]

New to the site. Just wanted to say I used these tips on a long road trip, and they helped a lot with saving gas! Thanks for all the hard work.

[givemeslack]

I'm surprised I didn't see in all the hypermiling tips, this obvious way to reduce a significant amount of weight. Fill up with gas more frequently, and only when the tank is near empty. Then fill up 1/4 to 1/2 of the tank capacity. That's much less weight than a full tank. As a side benefit, the gas will be fresher which is better for your engine.

[2000neon]

The problem with only filling part way is that it makes it virtually impossible to get accurate fuel economy numbers when only filling the tank up half way. A lot of us, myself included use tank-to-tank averages to calculate fuel economy. By filling up to a relatively consistent point (a full tank) I can figure out exactly how much fuel was used. By only filling up to a half or quarter tank, I can't tell how much fuel it actually took to drive X number of miles.

For example, from a full tank, if I drive 200 miles and it takes 4 gallons to fill up to full again, that was 50 mpg. If I start near a half tank and drive 100 miles, I could put in 1 gallon and guess 100 mpg, or put in 5 gallons which shows only 20 mpg. One thing that just about everyone here consistently agrees on, is that keeping up to date, accurate fuel logs is one of the most important things you can do.

[Gealii]

on top of what 2000neon said if you fill from 1/4 to 1/2 that means more stops compared to filling up your tank and draining to 1/4 which means more gas use from starting and stopping at a gas station and your own personal time as multiple stops filling 3 gal would take more time than 1 stop filling 10gal

[givemeslack]

I agree with 2000neon, that the downside to only filling half a tank means not easily getting accurate gas mileage that you would by measuring miles from fill up to fill up.

Fortunately one of my cars, a Maserati Coupe, has a mpg gauge. I'd much rather fill 5 gallons at a time for pleasure trips, than the full tank of 22 gallons in that vehicle, especially since I don't use it everyday, and gas does go stale. Driving it with only 5 gallons and less is noticeably faster, too. There's a reason why cars are stripped down for track racing.

Even without a mpg gauge, you can still use my method of only filling up halfway AND get an accurate reading. Start with a full tank, setting the trip odometer to 0. Drive and use up the gas almost to empty.

From then on, whenever the tank is empty, only fill it up half way, keeping a log of the gallons of gas put in, (or just save all the receipts). Do this as many times as you want, the more the better, and when you are ready to take accurate reading of mpg, fill the tank to the top again. Figure the mpg by the odometer reading, and all the gas added since the last complete fill up. Simple.

You can't deny that it's significantly less weight to drive with half a tank of gas or less, than with a full tank of gas, and this must increase the mpg. Gasoline weighs about 6 pounds per gallon. In a 22 gallon tank, that's like carrying an extra person.

And, so, I strongly disagree with Gealii. Pulling in to a gas station that is on your route, shutting off the engine, and filling up with however many gallons you want does not waste gas. It only takes a few minutes, and it's a good time to pull over and check the oil and tire pressure.

Either way you do it, it does make sense for several reasons to let the needle go all the way to 'E' before filling up.

[Fat Charlie]

Originally Posted by givemeslack

There's a reason why cars are stripped down for track racing.

There's also a reason that racers don't pit unless they absolutely have to. Personally, I'd rather carry more fuel and stop less. There's only one gas station in my area that gives a smooth in & out, and I have to take it up to 60 or so on the exit- not that nice on the mileage. Every other gas station around here involves a lot of screwing around in traffic to get in and out of.

Reducing your stops to get gas will probably be better for your FE than reducing the weight of the gas you're lugging around. Either way, you're completely right to take it down to empty before you gas up- but the accurate data you get by filling all the way up helps you take it down that far with more confidence.