Anyone overcoming gas prices by hypermiling?

[laurence]

CleanMPG, - What is hypermiling An authoritative source on fuel economy and hypermiling

A local radio station interviewed the founder of this web site and he briefly touched on some tips. I have to say I was intrigued. I drive a Volvo stick shift sedan which was getting me 26.5 mpg average. But even at that rate I was really noticing the pinch of gas prices. So I've tried some of his tamer steps. I'm wondering though, how dangerous are some of his ploys? For example, he suggests inflating your tires to the maximum pressure listed on the sidewall, as opposed to the pressure suggested in the manual. In my case, that would be 55 PSI instead of 33. I felt too nervous to go that far so chose a middle ground of 40 PSI. Get this, he "unofficially" suggests 25% OVER the maximum PSI but says he can't suggest that for legal reasons(?). Other steps are common sense (clean out your car trunk and back seat) and still others are extreme (Pulse and Glide - get about 5 feet behind a mack truck and turn off your engine, being drawn forward by his draft). I've been doing a compromise there where I'll come up somewhat close to the truck and push the clutch in to drop the RPM's to ~800 (Idle). In about 3 days of paying attention and doing little things like the tires and changing the air filter, I've got my cars computer to read 27.0 average mpg, and I think it's still got a ways to climb! What really grabbed me is this guy has an old Ford Ranger he's getting 65 mpg with! And he gets his Prius waaaay over 100 mpg.

So does anyone employ any of these methods? Anybody heard of this before? I figure if I can improve my fuel economy 10% without too much effort I can save about 3 tanks of gas/year. @ $4.00/gallon x 16 gallons it's only $68, but still. Hey, maybe I can get it to 20% if I can just learn to draft those mack trucks....

 

[RetiredGypsy]

By a horribly miss-calibrated air compressor, I once had 80 PSI in my rear tire on my motorcycle. I didn't know it was a problem (it didn't look bad and I've never heard of a badly calibrated air compressor) so I drove home at 80-90 MPH for 25 miles. Who knows how long I could have kept that up before some sort of catastrophic failure?

I think Mythbusters did a segment on drafting behind big trucks to get better MPG. It worked for them. I've heard from other sources that I trust that it helps. In the past I was never patient enough to try, and I've been behind too many big rigs that have kicked back crap into my helmet or windshield, or God forbid blow a tire.

I have no problem driving 60 MPH on the right hand lane. I get a respectable 50 MPG doing so. If I were to drop it down to 50 MPH I would get about 60 MPG, but I wouldn't feel safe at all in doing so. On the backroads, I have and do go 50 all the time, and constantly get about 250 miles to a 5 gallon tank. At 70-80 MPH, that figure drops down to about 160-180, so the difference is significant.

But the extremes that these hypermilers suggest, I don't like the trade offs. It seems like you could get into too many dangerous situations to save a little money.

 

[SecondCor521]

I do some of the tricks and may add a few to my repertoire. However, I am a bad driver to begin with so anything that in any way compromises my safety or makes my driving more complicated gets ixnayed. Any fuel savings you may get can easily get wiped out with one car or motorcycle wreck, either in repair bills to the vehicles involved or hospital bills for the people involved.

2Cor521

 

[DallasGuy]

I don't hypermile, but I do several things to increase my gas mileage...I keep tire air pressure at suggested max, drive no faster than 60 mph and use cruise control as much as possible to keep it there, I removed the back seats to remove weight from the vehicle since I drive 95% of the time alone (they flip out easily in my PT Cruiser), try to anticipate red light changes so I don't have to brake as much and have put in a different type of air filter that allows more air to burn the fuel more efficiently. I usually get between 27 and 31 mpg with my PT Cruiser which is near the top end of the EPA estimates for that car. I'm tempted to drive slower than 60 mph but as one other poster above stated, a person starts to feel a little unsafe going that slow on the freeway.

 

[ERD50]

At $68/year, I think you are losing money. Wear on your clutch throw out bearing, wear on your tires (they are not meant to be driven at that pressure). Safety issues alone make this a non-starter for me.

I'd also take out additional insurance, both medical and term life - that's going to cost more than $68/year. False economy.

But feel free, maybe you will catch the junk that falls from the truck, and save me from having to try to avoid it (at least I'll have some reaction time, following several seconds behind instead of drafting).

Contact patch - Wikipedia, the free encyclopedia

-ERD50

 

[Walt34]

Much of what the hypermilers do is too risky for my tastes. Drafting behind a large truck does work, but what is a minor bump to it can be catastrophic to even a large car - think deer carcass or muffler on the road. Staying that close behind gives you no reaction time. A second of inattention at the same time the truck brakes hard and you have the back of the truck literally in your face.

High tire pressures affect handling and reduces the "footprint" of the tire on the road to just the center section and will increase stopping distances. No deal for me.

So I just keep up with the maintenance, keep clean air filters in place, and drive with an awareness that every time I touch the brake it is "throwing away" expensive momentum.

Keeping the vehicles very clean makes some difference, the faster one drives the more it matters. When I had an airplane that cruised at 120 mph washing it would increase speed by 5 mph.

 

[Rich_by_the_Bay]

The Prius boards are filled with mileage-squeezing suggestions. Pulse and glide is very common and I have found myself doing it just out of habit in my Prius (~58 mpg in mixed commuting). I find the biggest help is to anti-tailgate so that when brake lights go on in front of me, I just coast without braking. 90% of the time, they have accelerated again before I get close enough to brake.

Drafting behind a truck is a great way to get 100 mpg for 5 minutes until you die. Not for me. Tire pressure - for me the trick is to keep it at, not below, recommended. I might push it a pound or two before a long trip, but find that the safety, comfort, mileage thing has been pretty much balanced in the recommended pressures.

 

[RunningBum]

My gas mileage drops off considerably the more over 70mph I drive, so now I keep it to 70. It seems that the diff between 65 & 70 is small, but 70 & 75 is large.

I only overinflate by 1-2 PSI. I agree that way overinflating is a bad idea, but do check to make sure you don't underinflate.

No thanks to tailgaiting behind trucks, the risk isn't worth it. I hate when someone rides on my bumper, I doubt truckers like it much better.

I've always tried to do things like coast into red lights, hoping to catch it green before I come to a complete stop.

The #1 thing is to just drive less. Try to group multiple errands, make sure errands get done right and I don't have to go back for one more thing, walk where I can, etc.

 

[Leonidas]

http://www.cleanmpg.com/cmps_index.php?page=hypermilingGet this, he "unofficially" suggests 25% OVER the maximum PSI but says he can't suggest that for legal reasons(?).

I guess that overinflation will decrease rolling resistance, but the tires would wear improperly and more quickly. Plus too much air pressure will make them overreact to road imperfections (grooves, bumps, potholes, etc.), and I bet they hydroplane like crazy when the road surface is wet.

 

[ERD50]

The #1 thing is to just drive less. Try to group multiple errands, make sure errands get done right and I don't have to go back for one more thing, walk where I can, etc.

Absolutely.

I routinely get an effective (person miles) 42 mpg, or even 63 mpg from my Volvo by coordinating with other parents and carpooling the kids to/from events. And one or two fewer cars on the roads increases overall safety, rather than reducing it. Wear/tear saved on car... Hey I even save a bit on insurance by staying under 7500 miles/year.

-ERD50

 

[maddythebeagle]

I do the same as RunningBum....it helps that I live in a smaller city and hit a few rural roads into work and work from home 1-2 days a week...group trips and probably will cut down on 1-2 longer trips this year...Still, looking at my previous monthly gas usage, the increase in gas prices is costing me 40-50 bucks more a month and most of my usage is reimbursed for work travel..

 

[tryan]

Tried drafting many years ago. Most truckers freak, and swerve from lane to lane to shake you ... not a safe experience.

Been combining errands. Even will wait for DW car to run out (rather than use the gas guzzeling SUV). Had to fill the truck yesterday .... cost $120!

 

[Bestwifeever]

I also heard a radio show talking about hypermiling and am glad to see it addressed here.

Is the maximum PSI printed on the tires themselves an unsafe pressure? Would that PSI cause uneven wear on the tires, does anyone know?

Also, any opinions on using regular vs. higher octane?

 

[TromboneAl]

The manual for our '02 Echo says to inflate to 35 PSI. When I bought our high performance tires, I was told it was OK to inflate them to the max, 44 PSI. Told I would get better mileage and the handling would be better. "What's the disadvantage?" I asked, and was told "Well, TromboneAl, the only disadvantage is that the ride will be rougher." The ride is fine, and we get 41-44 MPG routinely (mostly highway).

The other thing we do, that I've mentioned before, is drive 55 most times.

 

[windsurf]

Rich_in_Tampa said: "The Prius boards are filled with mileage-squeezing suggestions. Pulse and glide is very common and I have found myself doing it just out of habit in my Prius (~58 mpg in mixed commuting). I find the biggest help is to anti-tailgate so that when brake lights go on in front of me, I just coast without braking. 90% of the time, they have accelerated again before I get close enough to brake."


Like Rich, I have a Prius and use pulsing and coasting. The car's multi-display provides instant feedback via cool schematics that show your mode (engine/ electric motor or combo and associated real-time milage) that "teach" you how to reflexively drive efficiently. The anticipation becomes automatic. As Rich explains, you begin to anticipate stopping distance and, without thinking, use a friendlier foot on the pedals. I over-inflate the tires a bit (41 psi front and 38 rear) to decrease rolling resistance. Another issue is roof racks. An EMPTY roof rack cuts my milage by 4 or 5 mpg. A kayak up there cuts it by 6 or 8. I don't leave the rack on if it's not in use.

 

[tightasadrum]

I'm no longer thinking in mpg terms; it's more of fpm, as in fillups per month. Before I stopped w**king and commuting 135 miles per day I filled up the old Camry twice a week. Now it's twice a month, maybe. Just shows that not driving is better than higher mpg. It helps to live in a smaller community too; trips are shorter. And I find it useful to combine errands as much as possible. Being well invested in commodity futures that include oil makes the whole package a little easier to stomach.

 

[ERD50]

I also heard a radio show talking about hypermiling and am glad to see it addressed here.

Is the maximum PSI printed on the tires themselves an unsafe pressure? Would that PSI cause uneven wear on the tires, does anyone know?

It definitely can cause excess tire wear. Google 'over inflate' and tires for some links. That wiki link and others, showed how you can do a chalk line test on your tires to look for wear patterns.

Also, it can adversely affect handling and safety. True, mfgs probably have you inflate on the low side for added comfort of ride, but there are other factors in play that you may never realize until you try to react to an emergency situation. I don't care to find out that way.

Also, any opinions on using regular vs. higher octane?

Now, THIS is worth revisiting. I thought about it the last time I filled up. Here's what I know (and don't know):

A) Most cars today will run fine on all grades (check your manual). They adjust for the grades.


B) There is *some* evidence that a car can get slightly better mileage with the higher grade. It's slight enough to make it a bit tough to tell fill-up to fill-up.

C) The higher grade gas tends (I have not checked lately) to be a fixed amount higher (like 10 cents) than lower grade, rather than a % higher - this is important.


So, if you get say, 5% better mpg with high grade (say 21 vs 20), and it is a dime more, that is a wash at $2.00 gas. But, a dime added to $4.00 gas is a smaller % increase in cost, and makes higher grade fuel a good buy.

Even if those numbers are close - it's only about 2% gas price savings. But no risk, no effort.

So, anyone have good figures on premium vs regular mpg and cost delta?


-ERD50

 

[windsurf]

And I find it useful to combine errands as much as possible. Being well invested in commodity futures that include oil makes the whole package a little easier to stomach.

I jumped into Vanguard energy a couple of years ago and have watched the 25k smidge double. I wish I would have gone bigger. But, like you, I look at that gain as mitigation of the pump pain. Do you think energy stocks will "pop" one these days (as in bubble)?

 

[NotReady4Purple]

It's spring. I'm bicycling... That gets me down to one fillup per month.

 

[Zathras]

For me, drafting behind trucks is not worth the added danger to myself or others.
I will follow trucks at a standard distance and do a lot of other things that don't endanger me.
I find the biggest single helper is to use a light foot on the accelerator and brake.

 

[Leonidas]

I also heard a radio show talking about hypermiling and am glad to see it addressed here.

Is the maximum PSI printed on the tires themselves an unsafe pressure? Would that PSI cause uneven wear on the tires, does anyone know?

No, the max is okay. It's supposed to be for when you are carrying a heavier load than normal. But, make sure that you fill the tires when they are cold (haven't heated up from driving) or else you will wind up with overinflated tires. If you are at max pressure you will have to recheck and maybe adjust the pressure when the seasons change from hot to cold because you don't want to exceed the maximum. It's when you go past max safe tire pressure that you are going to have problems. Somebody overinflated the tires on my wife's car a while back and I didn't catch it in time to prevent the damage and I had to replace them because they had experienced some severe irregular wear on the tread.

 

[travelover]

Hybrids, especially, seem to benefit from blocking the radiator in cold weather, though my guess is that any car would benefit. I haven't done a rigorous comparison, but my mileage this winter seemed to stay in the low 30's vs last winter when they fell into the mid 20's on my Escape hybrid.

I suspect there is significant cooling of the engine from airflow in the engine compartment and over the catalysts. Too lazy to do a thermodynamics study.

Tire pressure is definitely worth watching and can be increased a bit over owner's manual recommendations without getting poor road contact or wear problems.

Just avoiding short trips helps a lot as the engine doesn't run efficiently when it is cold.

My 2 cents.

 

[tightasadrum]

And I find it useful to combine errands as much as possible. Being well invested in commodity futures that include oil makes the whole package a little easier to stomach.

I jumped into Vanguard energy a couple of years ago and have watched the 25k smidge double. I wish I would have gone bigger. But, like you, I look at that gain as mitigation of the pump pain. Do you think energy stocks will "pop" one these days (as in bubble)?

Yes. But the big question is when. But isn't that the whole reason for re-balancing your portfolio? My problem, and it sounds like yours too, is that I would prefer to have an even higher percentage in a well diversified commodity fund, so re-balancing some money out of the fund goes counter to my overall objective for now. But of course the risk is there that I may lose the huge runup I've got on paper. You plays your cards and takes your chances I guess.

 

[Leonidas]

I may have to correct myself. I can't find anything that says overinflation causes hydroplaning, but my non-technical feeling is that it should. Back when I had a j*b we would push the envelope pretty hard on driving and I hydroplaned on all four tires several times. There's nothing like going down the interstate sideways at 80, with no steering control, to make you very sensitive to things like tread wear and tire inflation.

 

[HFWR]

From the Rubber Association, heh...

Rubber Association - Proper Tire Inflation

Over-inflation can be a problem too. An over-inflated tire rides on just the centre portion of the tread. The smaller contact area means reduced grip on the road, leading to a harsh ride, handling issues (such as steering and stopping problems) and increased wear on tires and suspension components. Seventeen per cent (17%) of vehicles in Canada have at least one tire that is over-inflated by 20%.