Anyone overcoming gas prices by hypermiling?

[cute fuzzy bunny]

Believe it or not, that was a deciding criteria for a car I bought. I had it down to two that I liked about equally and couldnt make up my mind. One took regular, one took premium.

So I bought the one that took regular.

 

[ERD50]

re - ERD50 earlier post...

so you'll have to go back to the first page of the thread to see my original post where I said overinflation was not a good idea due to handling, safety and wear issues.

Sorry, you're right - I missed it as we were on page 2 already.

-ERD50

 

[laurence]

I've agreed with the consensus here on most things, but I noticed one person mentioned the cost of wearing out my clutch. If someone could expand on that, my thought was when I have a downhill on the freeway I can push it in and ride for the 1-2 minutes at 800 rpm instead of 3000+ and save gas that way, and it would not be that many more gear shifts a day. Would that really shorten the lifespan of the clutch?

 

[haha]

I've agreed with the consensus here on most things, but I noticed one person mentioned the cost of wearing out my clutch. If someone could expand on that, my thought was when I have a downhill on the freeway I can push it in and ride for the 1-2 minutes at 800 rpm instead of 3000+ and save gas that way, and it would not be that many more gear shifts a day. Would that really shorten the lifespan of the clutch?

I doubt it. But it could shorten your lifespan, as freewheeling down a hill get can hairy. Also, on a steep hill you likely would have to ride your brakes to stay anywhere near the speed limit. In any case, you are not saving much gas, as the engine is running on a closed throttle anyway.

In WW2 gasoline was rationed, and people frequently did stunts like this. Overall a bad idea IMO. Also, a real PITA to other drivers.

Ha

 

[TromboneAl]

Originally Posted by Bestwifeever
Re drafting behind a semi on the highway--wouldn't that hurt the semi's MPG to be pulling you along? I could see some sudden stops on the truckdriver's part to deal with that problem....
No, because you are in the air the semi already cleared. (which is a super simple explanation)

The only important thing is whether the (beer drinking, speed-taking, hairy-knuckled, pot-bellied, shaver-challenged) trucker thinks you are hurting his gas mileage.

 

[haha]

Hypermiling is crazy. Millionaires trdading a marginally increased gas mileage for an increased risk of death is not smart.

Ha

 

[Notmuchlonger]

Go Dale Go!

 

[haha]

Was he drafting when he bought it?

ha

 

[Notmuchlonger]

Dale Jarett? Nah just a UPS commercial. Hes retiring this year. He hasnt bought it yet. The whole drafting thing reminds me of Nascar something fierce...

 

[Nords]

I've agreed with the consensus here on most things, but I noticed one person mentioned the cost of wearing out my clutch. If someone could expand on that, my thought was when I have a downhill on the freeway I can push it in and ride for the 1-2 minutes at 800 rpm instead of 3000+ and save gas that way, and it would not be that many more gear shifts a day. Would that really shorten the lifespan of the clutch?

I'd say that in your neighborhood there's about a 1/365 chance of hydroplaning every year during the annual 90-minute rainstorm.

Overinflated tires-- bad tread wear patterns. There's also no forgiveness if you hit a bad pothole or scrape a curb or hit a patch of standing water. But as Leo says, right up to the upper limit of the tire is fine.

If you're going downhill with your foot pushing the clutch in, that's considered more wear than if you put it in neutral and take your foot off the clutch. It has to do with which parts stay spinning when the clutch is pushed in. But many manufacturers have changed their clutch designs in the last decade, so I'm gonna have to defer to a Volvo expert on that one. Hmm... strange... Andy doesn't seem to have acquired a Volvo board yet.

During my working days when I bicycled home from Ford Island, the causeway runs northeast-- right into the $%&ing tradewinds. It used to take me nine minutes of max effort to cross the 1.5 miles of road before I could turn Ewa-bound. However if I could happen to pull right behind one of the departing trolleys from the USS MISSOURI Memorial (with just a foot from my front tire to their rear bumper) then I could draft the causeway in under three minutes with very little effort. I got good enough that if I backed more than two feet away from the rear bumper, I could feel the back of the slipstream's turbulence start to tug. (Luckily the passengers never thought of throwing things or spitting over the back bumper. They'd just smile & shaka.) So to get the max advantage from a truck draft you'd have to be within three feet. They drivers wouldd probably never see you in their mirrors, so they'd never feel you slide under after they hit the brakes.

I think your best results would come from driving 55 MPH. Of course every other car on I-15 would ram you from behind, but you'd get great gas mileage from their pushes...

 

[Notmuchlonger]

Would you call that "bump" drafting Nords?

 

[samclem]

The auto manufacturers are pulling out all the stops to increase gas mileage, because they know higher mileage sells cars. They are spending big bucks to drill lightening holes in various components to save an ounce or two. All so that, on test day, the car might squeak out one more MPG. Given all this, and the known benefit to gas mileage of the relatively simple and no-cost step of increasing tire pressure, isn't it logical to assume that the max tire pressure listed on the doorframe/owners manual is really the maximum safe pressure to which you should fill the tires? On test day, the tires can only be inflated to the max PSI recommended in the manual. The max pressure listed on the sidewall is not the right number to use.

 

[Khan]

I see no reason to assume I can out think the manufacturers.

 

[cute fuzzy bunny]

If anything, I'd think they were already pushing it a bit.

I've been a little leery of my Pilots call for 5w20 oil...I think its getting 5w30 before the 110 degree heat sets in...

 

[LOL!]

I'm surprised this thread is concentrated on drafting and tire pressure. The two things that I do to increase mileage is coast, don't use my brakes, and turn off the engine at stop lights that I know are gonna take awhile. I get more than 20 mpg in city driving in my SUV. That may not be much to you Prius folks, but it's more than the EPA-rating for this vehicle.

Perhaps the most irritating to other drivers is coasting. I live about 3 miles and 6 stop lights from my job. I know all the light timings, so I will coast up to a half mile towards a red light or a light that is going to be red. Of course, the woman behind me in her Navigator or Sequoia or Escalade gets irritated and zooms around me towards the light at 10 mph over the speed limit only to slam on her brakes as the light changes to red. I coast up just as the light turns green and pass her while she is still stopped. It all repeats at the next light.

 

[ERD50]

I've agreed with the consensus here on most things, but I noticed one person mentioned the cost of wearing out my clutch. If someone could expand on that, my thought was when I have a downhill on the freeway I can push it in and ride for the 1-2 minutes at 800 rpm instead of 3000+ and save gas that way, and it would not be that many more gear shifts a day. Would that really shorten the lifespan of the clutch?

Not the clutch itself, but the throw-out bearing (in the clutch) life could be shortened. It has almost no stress on it until you actually depress the clutch pedal.

Manual Transmission: Pressure Plate

underline mine.

Description: The throw-out bearing, or clutch release bearing as it's sometimes called, is located between the clutch fork and the pressure plate fingers. The throw-out bearing only operates when the clutch pedal is depressed; the bearing is not designed for continuous use.

As haha stated - this is generally regarded as a bit of a safety issue. You are not quite ready to respond if you need to accelerate quickly, and w/o engine braking, response can be a but different than expected.

-ERD50

 

[HFWR]

Dale Jarett? Nah just a UPS commercial. Hes retiring this year. He hasnt bought it yet. The whole drafting thing reminds me of Nascar something fierce...

I think Ha was referring to Dale Earnhardt...

As for me, no tailgating tractor-trailer rigs! In fact, my rule is keep as large a space as possible, given the conditions, between me and EVERYBODY... Never know what the crazy f*ckers will do next. The motto in Dallas is "No move too stupid, no move too dangerous". It's better to cause a multi-car pile-up doing an illegal u-turn than to drive half a block farther to a convenient and safe place.

The added bonus to keeping your distance is gentler braking and acceleration, saving fuel and reducing wear on the vehicle.

 

[Texas Proud]

I am sure someone with more time can find the original article...

It was Car & Driver or Road and Track... when one of the hybrids were first coming out they had a bunch of car reviewers drive them and have a 'mileage contest'...

Since they knew that air drag was huge so they asked if they could 'draft'... they were told they could....

SO, they fixed up a shield on the back of an Excursion that let the car get right up to the back and draft... they won the contest... but some said they 'cheated'...

I do the coasting thing also.... and it is very funny to see people zoom around you again and again... they figure it out and the pull in front of you so you can not coast past them at the next light!!! OH well...

 

[homestead]

lots of folks are building hydrogen boosters to save gas
YouTube - Stan Meyer - hydrogen oxygen ( HHO ) - Zero Point Energy

One type uses electrolysis another type uses high voltage pulsing
circuit to get better than unity generation of hydrogen. see video above.

 

[free4now]

The auto manufacturers are pulling out all the stops to increase gas mileage, because they know higher mileage sells cars. They are spending big bucks to drill lightening holes in various components to save an ounce or two. All so that, on test day, the car might squeak out one more MPG. Given all this, and the known benefit to gas mileage of the relatively simple and no-cost step of increasing tire pressure, isn't it logical to assume that the max tire pressure listed on the doorframe/owners manual is really the maximum safe pressure to which you should fill the tires? On test day, the tires can only be inflated to the max PSI recommended in the manual. The max pressure listed on the sidewall is not the right number to use.

That would make sense, but there are other factors at play. My Prius came with very low rolling resistance tires as original equipment. They were relatively wimpy tires. When I replaced them with Michelin HydroEdge tires, I was putting on a higher quality tire with a higher speed rating, meaning it can handle higher temperatures without damage. It's naturally less likely to burst due to overpressure.

Also manufacturers of "family" type cars may be motivated to make the suspension feel cushy by suggesting a lower air pressure, simply because they think that's what people want.

There is the reality that tire pressure is always less, never more, in between checks. If you err on the side of overinflation, then if you forget to check your pressure every week you are fine. If you err on the side of underinflation then forgetting to check can take you into the danger zone.

Another thing to consider is that many people check pressure when tires are hot from driving. Heck, even tire stores do this if you drive your car in. If they adjust the tire pressure at that time they will effectively be underinflating their tires.

So I still think that leaning towards overinflation rather than underinflation is the way to go.

Overinflation causes problems when people are lazy in a different way, inflating the tire until it "looks full" which could be 80psi. But if you stick to the tire max pressure (often 44psi) and use a gauge you should be good.

 

[cute fuzzy bunny]

Side note: checked the tire pressure on my trailer tires for the first time in a few months.

Five in one and eleven in the other. Looked at the sidewall and they're rated for 90.

I turned my head a little when the compressor had them north of 60, just in case...

 

[ERD50]

Also manufacturers of "family" type cars may be motivated to make the suspension feel cushy by suggesting a lower air pressure, simply because they think that's what people want.

My Volvo S40 ( their 'entry-level' compact car ) gives two sets of tire pressure - comfort and fuel economy. 39F/36R for fuel savings, 31/29 for comfort. I'll be checking tomorrow - I'm not sure what they are at now. I'll be making some hi-way trips in the van over the next two weeks, so will def check pressure before I leave (I usually do anyhow).

I'm not sure that the dangers of over-inflation are related to the tire blowing out from the extra pressure - I think it is just that the handling of the car can be adversely affected. I just checked three vehicles, the tires all had a 'max' PSI, but they also all said 'follow the car manual/placard for PSI'.

And yes, under-inflation is bad, too.

-ERD50

 

[samclem]

lots of folks are building hydrogen boosters to save gas
YouTube - Stan Meyer - hydrogen oxygen ( HHO ) - Zero Point Energy

One type uses electrolysis another type uses high voltage pulsing
circuit to get better than unity generation of hydrogen. see video above.

Bogus. He lost a court case brought by the investors he hoodwinked:

From wikipedia: http://en.wikipedia.org/wiki/Stanley_Meyer%27s_water_fuel_cell

"Thus, if the device operated as claimed, the combustion cycle would start and end in the same state while extracting usable energy, thereby violating the first law of thermodynamics and allowing operation as a perpetual motion machine."

 

[A854321]

If you are going to go through the machinations to remove the back seats and draft very large trucks, you might as well shave your head and drive naked.

 

[homestead]

Bogus. He lost a court case brought by the investors he hoodwinked:

From wikipedia: http://en.wikipedia.org/wiki/Stanley_Meyer%27s_water_fuel_cell

"Thus, if the device operated as claimed, the combustion cycle would start and end in the same state while extracting usable energy, thereby violating the first law of thermodynamics and allowing operation as a perpetual motion machine."

I suppose nuclear bombs also violate that same law since the energy going in is just a few pounds of tnt.