5 Gasoline-Wasting Mistakes Most Drivers Make

Real driving conditions

I love how all these experts come out and tell us how we are wasting gas. Sorry I can't use any of these techniques, I drive in bumper to bumper traffic every day. Maybe the solution is better public transportation and better infrastructure. I wish I could get my car to optimal speed but it just doesn't happen

C Buzza of PA @ Aug 22, 2008 14:06:33 PM

GASOLINE WASTING MISTAKES

I drive a 2000 Chrysler concorde, a big car, with a 210 hp v6 engine and automatic shift. I try to adhere to the five points about driving mistakes by not making the mistakes. The results are average arterial street city driving of 23 to 24 mpg and highway driving of 33 mpg (not exceeding 70 mph on a freeway). that is better overall mileage than most middle size autos and some of the 4 cylinder smaller autos.

Guy Cook of UT @ Aug 22, 2008 13:55:32 PM

GASOLINE WASTING MISTAKES

I drive a 2000 Chrysler concorde, a big car, with a 210 hp v6 engine and automatic shift. I try to adhere to the five points about driving mistakes by not making the mistakes. The results are average arterial street city driving of 23 to 24 mpg and highway driving of 33 mpg (not exceeding 70 mph on a freeway). that is better overall mileage than most middle size autos and some of the 4 cylinder smaller autos.

Guy Cook of UT @ Aug 22, 2008 13:53:56 PM

MPG

I honestly believe the single greatest thing the US could do improve MPG is to do a better job of synchronizing the lights. I drive an Escalade, and do my absolute best to save fuel, but when I sit at lights for 3 or 4 minutes, waiting for them to change, with no cross traffic, it makes me crazy. The traffic lights need to all be designed, when there's no cross traffic, stay green, even if it's half an hour. I live in a congested area, and have no easy access to a freeway, but when I approcah a cross street, with no one waiting at that light, and mine goes red, you should be able to stop and go when the coast is clear, like right on red. I get 20 mog going 35 mph, 12 to 14 in stop and go, ridiculous. Before you all start, I need the truck for pulling a boat, and many times have 6 and 7 people in it.

bob of OH @ Aug 22, 2008 13:39:12 PM

Bob Stewart's "Peak Torque" mistake

Let me try to put Bob Stewart's mistake about driving at peak torque into understandable terms.

Two factors determine an engine's torque at any speed:

1. The combustion frequency (# of explosions per second)

2. The combustion efficiency (% of chemical energy converted into mechanical energy)

Combustion engines are most efficient at minimal speeds. Slower speeds give the engine more opportunity to take advantage of the thermal expansion from the combustion prior to spitting it out the exhaust. This is why lower RPMs almost always result in higher fuel efficiency.

The peak torque occurs when the marginal increase in torque due to increased combustion frequency is equal to the marginal decrease due to decreased combustion efficiency.

Or in other words...torque peaks when an engine becomes so inefficient that the marginal increase in combustion frequency can no longer make up for it.

Obviously, combustion efficiency drops off dramatically at high speeds. This is why a torque speed curve usually is linear and then suddenly drops off.

If Mr. Stewart thinks that driving at around 4000 or 5000 RPM is a good idea, he'd better have a big wallet.

pbireton of OH @ Aug 22, 2008 13:37:39 PM

Anticipation

One of the things any driver can do to improve fuel efficiency is to anticipate. By that, I mean don't race up to a stop light in hopes to beat the red. If you are a half block away from the light and it is green, you can bet your next paycheck it will turn red before you get there! If you see it turning yellow, take your foot of the gas and coast up to it. Not only will that save gas, but it will also save your brakes. Had a brake job recently? Think about what that costs and what few seconds of time you saved by stomping on the gas pedal to beat the red!

It just ain't worth it!

NASCAR drives their cars at over 150 mph. Guess what their mileage is? Of course that's racing but it does make a point.

I'm over 60 now, but when I was younger and gas was a hell of a lot cheaper, I did some of those things. Luckily I survived!

Another thing. Don't tailgate! Drafting only works at Daytona and Tallegeda! On the highway it can get you into a coffin!

Common Sense of CT @ Aug 11, 2008 15:58:28 PM

How slow is "too slow"?

"...The study, by Peter De Nayer, a former AA fuel efficiency expert, involved fitting cars with a fuel flow meter and testing them at Millbrook proving ground in Bedfordshire. He found that a Citroën C4 1.6 diesel achieved 99.6mpg at 20mph but only 29.3mpg at 90mph...

“There is a huge misconception that the most fuel-efficient speed is around 55mph. The study shows that the slower you go with the vehicle running smoothly, the less fuel you will use..."

http://www.timesonline.co.uk/tol/driving/article4107764.ece

XuYu of KY @ Aug 07, 2008 10:14:47 AM

running AC on Access. position

If you follow the advice of the writer and run your AC on left key side or ACCESSORIES you will get cool air for a brief time then run down your battery with only hot air coming out of the AC ducts. Wiyhout that engine running there is no AC cooling no matter what the dash instruments imply.

Harold D. Macking of FL @ Jul 19, 2008 11:46:43 AM