Hypermiling - is anyone trying it?

[Tom Sawyer]

I'd rather drive less often, and still drive the way I drive than to do everything that guy says he does.  I'd go nuts thinking about all of that stuff!   

Why not do both

[Paschale]

Well, some of the things I think I'll do naturally, like not putting the lead into it unnecessarily, but when you look at the link and the guy says things like "turn off the car before you put it in park" and all that other stuff, it just seems to get a little absurd.  Life's too short to worry so much about the price of gas going up--it's going to get higher the older I get, and it's just a fact of life that we all have to deal with.  I just think some of the guy's suggestions in that link are silly, that's all, and I know I will never do them. 

[DanG]

I know what ya mean, Paschale.  I've always driven rather conservatively, so there is less I can do to save gas than for a more aggressive driver.  Like you, there are limits as to how far I'll go.  I don't shut the engine off to coast, for instance, and I ain't gonna ride around in this heat with the windows up and no a/c.   There are other things I will do, such as not using the cruise control in the hills, and sometimes I'll turn the a/c on and off as needed, but I'll mostly continue doing as I have been.  I've always found that driving with dignity and consideration for others is safer, cheaper, and a lot less stressful.

I actually got pulled over by a trooper for not having brake lights, once.  He was surprised that the lights actually worked just fine, I just didn't use the brakes.

[StorminN]

Speaking of hypermiling, is anyone out there running one of those "underdrive" crankshaft pulleys? A couple of guys at work drive Ford Rangers, and are talking about getting them for their rigs. They are a slightly smaller pulley in diameter, I guess the thought is that most of the accessories will run fine at a little slower speed... it's supposed to add back about 12 hp and some mpg...

-Norm.

[Beweller]

Regarding the performance of cruise controls on rolling roads, I find that my vehicle maintains  a steady rpm on gently rolling roads.  Thus the effective gear ratio must remain constant and the throttle opened while climbing.  I cannot envision any improvement in fuel economy I could make by manually controling a constant road speed.  However, on steeper hills, the engine rpm increases and the fuel economy must fall below the best possible.  Overall, I would expect some loss of economy on a rolling road as compared with a level road.

Some of the increased fuel consumption accompanying hill climbing and acceleration performs a needed function and cannot be avoided.  The potential or kinetic energy of the vehicle must be increased, and this requires the expendature of fuel.  However, this energy is recoverable--with some efficiency loss-- when descending or coasting (decelerating without braking).

For a theoretical vehicle weighing 3200 lb and having a brake specific fuel consumption of 0.0849 gal/hp hr (thermal efficiency of 25 percent), climbing a one percent grade uses 0.00765 gal/mile to provide the increased potential energy.  This may sound trivial, but if the vehicle gets 25 mpg on a level road, the economy will fall to 21 mpg on the grade.  On a five percent grade, 13 mpg.

Acceleration increases the kinetic energy of the vehicle.  An acceleration of 0.22 mph/sec is equivalent to a grade of one percent and has the same effect on fuel consumption.  Small accelerations/decelerations occur almost continuously in ordinary driving.

If the vehicle free wheels and the engine is stopped during descending/decelerating, the recovery of the potential/kinetic energy may be 100 percent effective.

[StorminN]

OK, so on this last tankful, I didn't try hypermile...   I just... took it easy... tried not to have sudden stops or starts, coasted down some of the big hills, etc. I got 26.5mpg, about 1.5 mpg higher than the average of the past six tanks.

I have removed the roof rack from my car and pumped the tires up to about 40psi. Other than that, I think part of the difference may be that I used Chevron fuel this time... the car seems to run better on this than on the Costco or Safeway gas... but who knows... the Chevron pump still says "May contain up to 10% ethanol", so maybe it's all in my head...

-Norm.

[Fla._Deadheader]

 In the old days, 60's, I could NEVER get decent mileage using Esso or Sunoco.

  I believe what you say might be happening. Back then, the Tankers DID have the correct name on them, even if they DID all sell the same gasoline 

[Furby]

Roof racks reduce mileage by 1 to 3 mpg based on my tests and talking to folks that have done the same sort of tests as I have.
Simply having 4 towers, with two 4' bars across was cutting my mileage about 1.5 mpg or a hair more.
My current roof rack system is in the 2-3 mpg loss area.

[sprucebunny]

Here is the tool to teach you how to get the best mileage out of your car. It works on almost anything with a "OBDII" plug.
Can't wait to see if it works on my diesel 

 


This is an 'instant read' ... it also tells you trip averages and other stuff..... wish the car got 27 all the time 

It's a "ScanGauge II ". It will take a long time to save enough gas to pay for it at $170 but it can also reset codes from the computer.
My 1997 4runner has 240k miles on it and I can get 22+ in mixed rural driving in the summer.

The roof racks don't come off, though 

[Ron Wenrich]

That's exactly like the one I have.  It will help show you where you waste the most gas. 

I also get to notice when some tanks get better mileage than others.  Could be the amount of ethanol in the gas, which is what I expect.  I also suspect they go over that 10% mark.

[arojay]

Something that few of us think about is airflow.  Over 50 mph, rpm has less effect than aerodynamics. 
Some things you can do about it are grill covers, take off roof racks when they aren't needed, even open windows can make a difference.  I'm sure there are others.  I have been driving as conservatively as I can remember to be, for quite a few years now.  I put on lots of personal miles and I've been trucking on and off for about 30 years.  It does make a difference to find the optimum speed for a given application.  Progressive shifting makes a big difference with manual transmissions too.

[shinnlinger]

Hi,

I, like a few of you, thought this was a hyperMILLING link and passed it by, but now this is interesting.

In NH there are plenty of hills to coast down so what they hey, slide the powerjoke into neutral.  I did shut the moter off once, but the ol one ton is a bear w/out power breaks and steering.  Maybe if I get the old Toyato on the road again....

NOw about this European Diesel thing.  I was in England a few years ago for a wedding and remarked at all the Diesels running around, particularly from Ford, and wondered WHY NOT IN THE US?  I mean if the have Diesel focuses there, why not here?  Its the same company and they already developed it. The Diesel jetta is a hot item here and has no competition.  I was also astonished to see the Maxi, Fords version of the Mercedes/Dodge/Freightliner sprinter (another hot US seller) was running on a frickin 2 liter Diesel (ok it may have been 4 liters, but way smaller than my 7.3).  Now this thing can go on the freeway just fine and haul as much as my F-350(If not more), but why isnt the small efficient diesel available here?  Shove that in an F-150 and away you go.  It is even ULSD compliant as that is what they have had over there for a while, so the bugs might even be worked out.

I dont think it is an EPA thing at all.  I recently read in FARM SHOW that the late '70's/early 80's chevy diesel 350 was such a POS that it turned Americans off from Diesels...gave them a bad name, but I think the real reason is this....You may have heard that Ford, in light of the recent slump in the truck and SUV are now going to import these European gems and start making them here in an effort to appeal to consumers.  I think this is a good idea, but a finacial analyst said even if they sell like hotcakes, the company may still be in trouble as the PROFIT margin is not as good as on an F-150 or SUV.

SO there you have it.  Those companies haven't been selling us these more efficient rigs because they are inferior, but rather because the dont make AS MUCH $$$ as the junk that we are now stuck with.

Rant over.

[Gary_C]

 SO there you have it.  Those companies haven't been selling us these more efficient rigs because they are inferior, but rather because the dont make AS MUCH $$$ as the junk that we are now stuck with.

Unfortunately, there is more to it than that. In the US, we now have clean burn regulations (soot and particulate) on diesels that the EU has not adopted and which those European diesels cannot pass. In the US, the VW diesel just barely passed this last year and has had some reliability problems with that diesel engine.

This is also why both Ford and Dodge have had to come out with new versions of diesels in their light trucks. The old 7.3 diesel could not pass any soot emission regulations.

The heavy truck engines in the US, Cummins, Cat, Detroit and others have also had to comply and are having some problems with that clean burn technology. Unfortunately that latest technology clean burn engine gets worse fuel economy than its previous version.

So you have to blame the cleaner air you breathe as the real culprit.

[Toolman]

I love my scan guage. It saved me alot on fuel consumption by pointing out my bad driving habits. It is worth every penny!!

[shinnlinger]

Gary,

I appreciate that the NEW (2008) clean burn regulations complicate things a bit, but these diesels have been rolling around Europe for DECADES.

If They can make the big rig engines pass emmisions, they can make the small ones pass too.....

IF they wanted to

Yes there were problems with most of the Diesels making compliance this year, but like you said the VW engine PASSED.....barely, but it passed.