Hypermiling

[sundev]

I did a few searches in this forum about hypermiling and couldn't find much other than people freaking out about coasting in neutral.

Has anyone tried any of the techniques that hypermilers use? I recently received a Scangauge II and in trying some of the techniques the mileage increase is pretty amazing.

Some things I have tried:
- Pulse & Glide
- Drafting
- Driving without brakes (i.e. planning your driving better)
- Inflating tires to sidewall max

BTW I have a 2008 Eclipse (A/T). I averaged 37 mpg according to my SG II on my drive to work, which is 55% city and 45% highway driving. The EPA estimate for my car is 26 mpg highway.

 

[PingSpike]

I don't know what pulse and glide is. I try to use my brakes less, and get away with letting hills jet me up to high speeds and then just coast until I slow back down. I figure that saves wear on the brake pads as well.

The trouble with using brakes less in traffic is that to really do it right you end up leaving large distances in front of you. This results in slow ass morons and large trucks cutting you off half the time.

 

[LTC8K6]

Technically you can't glide unless you have a hybrid where the engine shuts off.

I suppose you could shut your engine off, but I wouldn't.

 

[SearchMaster]

I don't necessarily use HM techniques but I have changed my driving habits after Katrina. I accelerate a bit more slowly (not obnoxiously so, just don't race from stoplight to stoplight), brake less, etc. and the mileage on my Maxima has gone from ~22 avg to ~27 avg. My wife bitches about the mileage on her Odyssey all the time and I try to convince her that she CAN improve it fairly simply but she won't listen. I had to use her van a couple of weeks ago and averaged ~23 whereas she gets ~18.

 

[Foxery]

Choose your strategies wisely, as some of the hypermiling tricks are somewhat unsafe, or cause wear and tear on other parts of the vehicle. Drafting trucks is illegal in some states.

That said, the general gist of driving via anticipation rather than reaction will lower your gas bill, your general maintenence bills, and your blood pressure.

 

[radioouman]

I have a 60 mile commute, and I drive a car with a long term average of 26.5 mpg. I decided to see what kind of mileage I could get, so I accelerated extremely slowly, timed my driving so that I would hit green lights, drafted behind trucks (two car lengths), kept a constant throttle going uphills and made sure to have a draft vehicle, and accelerated going down hills. I was able to get my mileage up to 35 mpg until I had to get off the highway, and then it dropped down to 33.

I did this test during the day when there wasn't much traffic at all. It would have been a little annoying to other drivers, and it wouldn't be possible if there was much traffic.

 

[thomsbrain]

Originally posted by: LTC8K6
Technically you can't glide unless you have a hybrid where the engine shuts off.

I suppose you could shut your engine off, but I wouldn't.

Pulse and glide attempts to capitalize on the fact that your engine is more efficient at wider throttle openings, and many cars shut off fuel flow completely when coasting in gear. Essentially you create a little "hybrid" system using momentum energy instead of electrical energy. You use the engine to its full potential (and maximum efficiency) for a short burst, then "shut it off" by coasting in gear and drive on the momentum you created. It would really only work effectively on a manual transmission, where you can prevent downshifting or torque converters unlocking during the pulse. Obviously, it would work better it you really could shut off the engine and coast in neutral during the glides, but that would kill your starter and be dangerous. Personally, I'd find all this to be way too much trouble.

I used hypermiling techniques for a tank of gas once and improved from 26 MPG to 29 MPG, but it was hard to justify the extra anxiety. That said, I seem to have carried the "just say no to the brakes" attitude into my normal driving, letting off much earlier and coasting. That's just a better overall driving technique, IMO, since it decreases wear-and-tear.

 

[theeedude]

- Pulse & Glide
Not turn off engine, but neutral, yes.

- Drafting
Yes, really helps highway mpg.

- Driving without brakes (i.e. planning your driving better)
Yes, I let off gas before intersections until I am sure the light will be green.

- Inflating tires to sidewall max
No, don't want weird wear pattern.

 

[LTC8K6]

You will probably burn more fuel in neutral than in gear in an auto.

 

[sundev]

Originally posted by: LTC8K6
You will probably burn more fuel in neutral than in gear in an auto.

That's true, however you can coast a LOT further in neutral than in gear, at least in my car. That being said, 90% of the time I coast in gear.

 

[Uhtrinity]

Originally posted by: sundevb
I did a few searches in this forum about hypermiling and couldn't find much other than people freaking out about coasting in neutral.

Has anyone tried any of the techniques that hypermilers use? I recently received a Scangauge II and in trying some of the techniques the mileage increase is pretty amazing.

Some things I have tried:
- Pulse & Glide
- Drafting
- Driving without brakes (i.e. planning your driving better)
- Inflating tires to sidewall max

BTW I have a 2008 Eclipse (A/T). I averaged 37 mpg according to my SG II on my drive to work, which is 55% city and 45% highway driving. The EPA estimate for my car is 26 mpg highway.

I use safe hypermiling techniques all the time. My City average has been running around 60 mpg, while highway has been 70 - 100 mpg. The biggest thing is to slow down, don't drive aggressively, and be proactive like another poster said, not reactive.

For the last week I have also been running PHEV (plugin hybrid electric vehicle) plus hypermiling techniques, and my city average has been running around 85 - 90 mpg average. In fact I made a trip to the store yesterday and did 135 mpg over 6 miles in town.

 

[halik]

I've been doing the neutral coasting and using momentum and potential energy (ie hills) to do my driving. I'm averaging around 21mpg mostly city (audi 2.7T)... i do need new oxygen sensors though.

Does drafting only work on trucks, or can you draft off regular cars?

 

[PlasmaBomb]

It works well with trucks as they leave a bigger wake behind. Only problem is finding one going at your desired speed.

 

[fstime]

I wouldn't inflate the tires to their max, your tires will wear irregularly, make your ride quality worse, and you will have a higher risk of damaging something from potholes, curbs, debris, etc..

 

[jagec]

Originally posted by: thomsbrain
Obviously, it would work better it you really could shut off the engine and coast in neutral during the glides, but that would kill your starter and be dangerous.

Why would you use the starter? Leave it in gear and use the clutch. It would increase wear slightly, of course, but better than using the starter.

I enjoy driving, so I don't usually use those techniques. If I'm towing a trailer, however, I do. Normally I ride a bike, and while I suppose I could probably improve my mileage a bit using those techniques, I'm willing to live with 55mpg and have more fun and be more safe doing it.

 

[GoingUp]

I do pretty much everything but the drafting.

 

[charrison]

I just slowed down a bit and on my last tank got 26mpg. I typically get 23 with a 50/50 driving mix. This is not bad at all for a car that is rated 19/25

 

[alkemyst]

i just throw a chain to the car in front of me and coast.

 

[sundev]

I averaged 40 mpg driving home last night (according to SGII) and 37 mpg driving to work today again. If this keeps up, even at 35 mpg, I'll be saving about $60 a month in gas.

Pretty amazing.

 

[Vetterin]

I also use some of the above stratigies but always come to my main gas saving law that every 10 mph over 60 reduces fuel economy by about 4 mpg, a figure that remains fairly constant regardless of vehicle size.

 

[Uhtrinity]

Originally posted by: Vetterin
I also use some of the above stratigies but always come to my main gas saving law that every 10 mph over 60 reduces fuel economy by about 4 mpg, a figure that remains fairly constant regardless of vehicle size.

This is fact for most cars, but going by a percentage is more accurate. If my car only lost 4 mpg for every 10 mph I would be driving faster

As it is:

45 mph - +90mpg
55 mph - ~75 - 90 mpg
65 mph - ~ 70 - 75 mpg
75 mph - ~60 - 70 mpg
85 mph - ~50 mpg
Of course road conditions, weather, temperature all play a role.

 

[duragezic]

Is the gas prices why people seemed to drive slower on the interstates? Where I'm from all of my life, there is no such thing as freeways, ramps, exits and that sort. So on a trip through Michigan to New York, it was like my first time on such roadways, but I had expected either from hearing from other people or riding in the car when I was younger that people on I-75 and similar haul ass completely and go like 85mph.

I get on I-75 and set the cruise to 75mph, figuring it is fast enough and I'd avoid speeding tickets. Well damn, like the entire way from Michigan to NY, going 5-7mph over the speed limit, I was cruising by 90% of vehicles! Only spotted a handful of vehicles in my rearview that were clearly hauling ass. Yet the same people who barely went the speed limit also did not seem to do a single thing while going through construction or areas with a limit down 10 to 15mph for those few miles. So I'd blow by them going 5mph over only to hit construction at 55mph and go no more than 60mph to have them cruise by at 70mph.

 

[Howard]

Originally posted by: BouZouki
I wouldn't inflate the tires to their max, your tires will wear irregularly, make your ride quality worse, and you will have a higher risk of damaging something from potholes, curbs, debris, etc..

Who says nominal max is overinflation?

 

[luv2liv]

my friend got up to 75mpg on his.
i forgot which car he drives though. definitely not a prius or one of those hybrids.
it was pretty impressive!!

 

[0roo0roo]

Originally posted by: Howard

Originally posted by: BouZouki
I wouldn't inflate the tires to their max, your tires will wear irregularly, make your ride quality worse, and you will have a higher risk of damaging something from potholes, curbs, debris, etc..

Who says nominal max is overinflation?

sidewall max is max possible. actual max for each car is different. for most cars tirewall max is definitely over inflation.
and its not worth the safety loss... basiaclly you bulge the middle out and lower your grip area.