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That thing about the open windows on the highway not making a difference in fuel economy was news to me.
Not sure I agree with your statement about the biggest myth being what the manufacturer says the vehicle will get. I think that the main reason people are unable to get the MPG figures that are stated on their window sticker is that they just drive too damn fast! If your car is rated at, let's say 40 mpg on the highway, you're not going to get that figure if you go blasting down the highway at 75 or 80 mph. I am just amazed at all of the people who routinely ignore posted speed limits these days, even with gas prices as high as they are. I took my car out on the highway yesterday driving to meet a friend about 70 miles from where I live. The posted speed limit on the highway I was using was 65 mph, which seems pretty reasonable to me. I had the cruise control on my car set at 70. While I was driving 70, nearly every car on the highway was passing me! These people must have awfully deep pockets, or they just don't care about fuel economy to be driving that fast.
I remember hearing on the radio that the best speed to drive on the highway for most vehicles to get maximum fuel economy is around 60-65 mph. When you drive faster than 65 mph, your fuel economy drops off noticeably.
I agree. Good point!
I drive with the windows down and my sunroof open on my Jeep all the time. My milage never changes, be it town driving or at 65 on the highway. I just turn the radio up.
However, regarding fuel economy...my Jeep is rated for 23mpg highway. I can get 24 running 75mph. Speed limits around here are between 65 and 70, with it being 70 farther south. But yes, fuel economy is not something I generally worry about, or I wouldn't have bought another SUV.
Ya got me there, Mike. I actually was going to set the cruise control at 65, but given how fast everyone else around me was driving, I sort of felt pressured to set it higher.
Ya got me there, Mike. I actually was going to set the cruise control at 65, but given how fast everyone else around me was driving, I sort of felt pressured to set it higher.
hahahaha! If you take the "can't beat em, join em" approach, it still makes you one of them.
I used to cruise at 75 mph on my Civic and drove on highways about 75% of the time.. I got the EPA expected MPG (0.25*CityMPG + 0.75*HighwayMPG).
When gas prices rose and I started to cruise at 65 instead, my average MPG ended up higher than the rated Highway MPG (even though there was some City driving mixed in).
Many of the "myths" around depend on the car. A clean air filter makes a difference on many of my cars. They are older cars. Warming up may also make a difference. Some of my cars get a huge difference if there are two or more people inside instead of one. Some of them it makes no difference with 7 people. With some cars wind or hills make a signficant difference, with others it is negligible. For some cars (older) elevation makes a huge difference in mileage. Road surface can make a noticable difference. dirt roads when wet, produce especially terrible mileage. Snow and Ice can make a huge difference too.
I usually drive 80-90 on the dry freeway without traffic. In some cars gas mileage drops very substantailly compared to 65 or 70, in other cars there is no measurable difference.
Most cars get lower mileage on premium gasoline, maybe all cars do.
Bypassing the converters does not automatically produce better gas mileage (sometimes you have to modify the computer).
New cars do not get better mileage than older cars (older cars did not have the emissions garabge and were not weighted down with loads and loads of safety equipment - I had a 52 MPG car in the 1980s).
Keeping your gas tank half empty will not produce better mileage (some beleive the reduced wieght will increase mileage - it probably does, but not by any measurable amount).
The best way to increase gas mileage is to ease into the pedal and keep the engine under 2000 rpm. But what fun is that?
Drafting will also massivey increase gas mileage, but it is incredibly dangerous and stupid.
There are no bottles of stuff you can pour into your gas tank that will significantly improve gas mileage.
Magnets or water injection do not improve mileage, not will mounting a pyramid on your dashboard or hood. (And BTW painting flames on the side of your car will not really make it go faster).
One true fact: Cars with two or three carbureators get worse gas mileage than cars with 1. (With a few excpetions).
A dirty air filter doesn't affect fuel economy CR said this was the case although their test car accelerated more slowly with a dirty air filter. Well duh. Then what would someone do? They would press the gas pedal more, using more gas to accomplish the same goal. Does CR think people will just accelerate more slowly?
Actually, unless they press the gas down far enough to go into open loop, with a dirty air filter the *throttle plate position* will be greater, but the *mass air flow* will be the same, so they will burn the same fuel - no?
I think this is true with any FI car, including my old K-Jet VW. Except the K-Jet in the 'roc does not have any open loop operation.
CR's point is that in contrast to a carburated car, where the air filter is quite important to fuel economy, it has little effect on FI cars.
I think it's funny when people roll down all the windows all the time instead of using AC to "save money on gas" or because their AC doesn't work... only to eventually have a window regulator (or all of them) break. A windows regulator is an expensive (several $$$ each), time consuming repair, a lot more expensive than the miniscule amount of gas they're saving, and if multiple power windows go out, more expensive than the cost to fix the AC.
I think it's funny when people roll down all the windows all the time instead of using AC to "save money on gas" or because their AC doesn't work... only to eventually have a window regulator (or all of them) break. A windows regulator is an expensive (several $$$ each), time consuming repair, a lot more expensive than the miniscule amount of gas they're saving, and if multiple power windows go out, more expensive than the cost to fix the AC.
I sometimes drive with the windows down and the A/C on. So I get the nice breeze from the windows and still get some cold air on me as well. Inefficient as hell I know, but I do enjoy it time to time.
What are you talking about the windows regulator? Are you suggesting they do not last as long when driving with the windows down than driving with the windows up? Can you enlighten me why this would be?
I'm not sure what you mean by expensive, A replacement part is $30 for the passenger window and $45 for the drivers window for my Honda Civic. My Civic is pushing 9 years now and I never had issues with the windows. I've never repaired one on a Honda civic, but I have on a Mercury Cougar. What you do is after removing the decorative inside paneling of the car, take a jigsaw to the door and make a nice big opening in the door to work with. So long as the paneling covers the hole you made, you don't have to worry about trying to work with the factory holes they give you in the door.
Just looked at a video for replacing a Honda Regulator, The holes in the door to access the regulator are far more generous than I remember on my old cougar. But the basic theory stands, if you have trouble accessing it, cut the metal to make the access holes bigger to allow access.
Last edited by TechGromit; 07-24-2012 at 08:43 PM..
I think it's funny when people roll down all the windows all the time instead of using AC to "save money on gas" or because their AC doesn't work... only to eventually have a window regulator (or all of them) break. A windows regulator is an expensive (several $$$ each), time consuming repair, a lot more expensive than the miniscule amount of gas they're saving, and if multiple power windows go out, more expensive than the cost to fix the AC.
I don't care about gas. I prefer driving with a breeze blowing through the car. I have 5 windows, I have them down as often as possible.
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