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Hypermiling update

Posted by admin on Aug 21st, 2008
Aug 21

I’ve been doing some more experimenting with hypermiling lately. One big thing I’ve found is that 40mph is kind of a sweet spot for driving efficiency for my car (the 2007 Dodge Charger). The way I know this is because of how the car coasts. If I’m going 50 on level pavement, and I put the car in neutral to coast to a light or stop sign, the speed quickly drops at a rate of about a mile a second until it hits 40mph. Once it hits 40 then it drastically changes the deceleration and is about one mile per 5+ seconds. It has proven to be very consistent.

What this tells me is that, if possible, I should try to typically drive no faster than 40mph on surface streets. Doing so will significantly reduce drag, increase overall efficiency, and overall mpg. This has altered my driving a bit and I either try to avoid higher speed streets, or I end up not always “keeping up” with the other drivers and actually driving the speed limit more often. Even though my driving style needed to be altered to accommodate for my findings, it’s all worth it in the end – for at least two reasons. One is the increased mileage, and two is the less aggressive driving style. Of course there are negatives too – most commonly, more people tailgate me now. I’ve learned to ignore them.

I’m not going to have as many opportunities to practice my hypermiling in the car starting in about a week. I bought a motorcycle for my daily commuting and my wife will start using the car as her daily driver instead of the Yukon (yes, the full sized SUV. Can’t trade it in….). She is also going to be getting a scooter soon so the car may end up sitting for long periods of time in the near future. Between my motorcycle and her scooter, we’ll be going from around $450 a month in gas to about $100 a month, as well as producing a lot less CO2.

Hypermiling success

Posted by admin on Jul 26th, 2008
Jul 26

Finally, I’m starting to get closer to my goal of 25 mpg in the Charger. On my last tank of gas I made it 381.8 miles, which took 16.07 gallons to refill. That comes out to be 23.76 mpg! Now that’s much better than the 17.5 mpg I used to get while commuting back and forth to work. That’s about a 35% increase in mileage – not too bad.

The biggest differences I made this time was to be more conscious of when I could coast, and I left the car in neutral at lights. Also, I only needed to accelerate hard twice – both while getting on the freeway with a short on-ramp. I only used the freeway about 1/3 of the time so most of this was on surface streets. I actually feel that I can get better results by using surface streets rather than the freeway since I have more opportunities to coast, and since the freeways in Los Angeles are usually stop and go anyway.

This weekend my wife and I are driving to Las Vegas in the Charger – we’ll see just how well we do with all of that freeway driving.

The results are in….

Posted by admin on Jul 17th, 2008
Jul 17

I’m neither pleased, nor displeased with the results of my first hypermiling attempt. I know there are more improvements I can implement to further increase my overall mileage and I will continue to research and implement them, but for now I’m just going to have to live with the extra 2.5mpg I got. My average mpg on a tank of gas before this one was usually 17-18mpg, on this tank I got 20.01mpg. Not quite what I was hoping for – only a 13% increase.

You may be wondering why I’m not more excited about these results? I really did set my expectations pretty high. I figured that if I could coast for at least 1 mile of my 12 mile commute that it would make a huge difference. I have lots of opportunities to coast along my route and was usually pretty good at taking advantage of them. I honestly was hoping for 25mpg. A point of clarification I feel I need to make – when I refer to “coasting” I mean take the car out of drive and put it in neutral. I usually only try to do this when I know I’m coming up to a stop, since putting the transmission back in gear while at driving speeds seems to produce a healthy “clunk” when re-engaging the gears.

I’m still “perfecting” my coasting abilities so I still expect to see an improvement going forward. For example, one thing I found to be consistent was if I had my windows rolled down, even just as little as 2 inches, I wouldn’t coast as well. Also, I need to start my coasting earlier to get the maximum advantage of the kinetic energy. I *know* that 25mpg is achievable.

I’m not sure if it’s going to help or hinder my progress, but I’m going to be starting a new job at the end of the month that will increase my commute, put me in more traffic, pretty much keep me off of the highways, and also take me over a large hill (I think they are called Encino Hills?). It may help though because once I get over the hill I can coast for up to three miles one way, and about a mile and a half in the other. I’m sure it will be a wash but it will also depend on how I ascend up those hills. As always, I’ll post the ongoing results.

Hypermiling – the “pre”-results

Posted by admin on Jul 17th, 2008
Jul 17

I should wait until tomorrow to post this since I don’t really have results yet, but I’m just too excited to wait. On the current tank of gas in my 2007 base model Dodge Charger I’ve been implementing some hypermiling techniques. I’ve inflated the tires to their maximum recommended pressure, have been coasting as much as possible, and try to not push down the gas pedal more than 1/4 of the way at any time. Normally I get about 17-18mpg, and on the last tank we got 21.84mpg – but that was mostly due to a round trip to San Diego on all freeways. Hmm – a quick check of the Dodge site shows me some disheartening information. I checked the 2008 SE model and they claim to get 18/26mpg. Lies – all lies I tell you. I’d be ecstatic if I got 26mpg. At least now I have a solid goal to strive for.

Anyway – the current miles on this tank of gas is 340. The tank holds 16-17 gallons, which gives me approximately 20.61mpg. Not as great as I was hoping for, but I’m just starting out and it is at least 2mpg more than I’d be getting normally so I’m not disappointed. I’ll update tomorrow after I fill up and run the numbers.

I should also mention that there has been an unexpected benefit to my hypermiling experiment. I seem to be much less aggressive on the road and I don’t really get upset at other drivers anymore. So at worst I’ll get 2mpg more and a less stressful commute.

See you all tomorrow.

Hypermiling anyone?

Posted by admin on Jul 2nd, 2008
Jul 2

Something I’ve been reading a lot about lately is something called hypermiling. Hypermiling is essentially the art of maintaining a vehicle and driving that vehicle in the most efficient standards. For example, the tires on my car have a maximum pressure of 44 psi. I used to inflate them to about 35 psi – a number I’m not certain how I came about – but have recently inflated them to their max pressure. This will help to reduce the rolling resistance and should increase fuel economy by approximately 10% (according to most articles I’ve read).

I’m also coasting a lot more. I’ve found that my car, even uphill, maintains a pretty steady rate of speed when coasting. This means that I can lay off the gas several blocks before I need to stop which saves a lot of gas on rural streets. On a flat, straight road I’ve let off the gas as far away as 1/8th of a mile before I needed to stop and I hadn’t even dropped 5 mph by the time I got to the stop light/sign! I bet that I could coast for a total of as much as a mile on my 12 mile commute to work.

If what I’ve read is true then these two practices could increase my MPG by as much as 3 miles per gallon. That’s a lot! I usually get an abysmal 17mpg in the car (2007 Dodge Charger) so 20mpg would be a great start to lowering my transportation footprint. I’m really curious to find out just how much of a difference it is going to make. I’ll report back in a week or two to update on the results, and possibly with some additional tips.