51.1 MPG.....
Keep that car as long as possible. My wife's Civic will get 37-38 on the highway with the A/C on. Its hard to drive 55 in south FL without getting run over by an 18 wheeler.
Increased gas mileage by >10% in my VW 1.8T
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Keep that car as long as possible. My wife's Civic will get 37-38 on the highway with the A/C on. Its hard to drive 55 in south FL without getting run over by an 18 wheeler.
So do you agree with Craig that if one coasts in gear, even though RPMs remain higher than coasting in neutral, less fuel is used? That's the part I'm having trouble understanding.
Are you saying that when coasting in gear, the vehicle's inertia is 'driving' the RPMs higher than if coasting in neutral, but the gas consumption is lower b/c injectors are cut off? And when coasting in neutral, though RPMs are lower than coasting in gear, more fuel is used b/c the injectors are not cut off?
On the local news last night they were talking about how driving your Camry at 65 mph gets you 30 mpg. Yet if you drive at 55 mph you get 40 mpg in the same car. Some how I really don't believe the numbers on that one. 2 or 3 mpg difference I can see but come on 10 mpg or 33 percent increase. When they say the people in the media are morons they were not kidding.
That's possible, you know. Maybe they drove the Camry @ 65mph going uphill and then drove it back @ 55mph going downhill. The folks in the media are certainly not morons, they're masters at drawing attention to themselves.
Yep, PRND3L, you got it. Fuel injectors cut off when coasting when rpms are higher than idle (actually, I think some turn back on just above idle if you are coasting down). So, IF you want to slow down or stop, keep it in gear! You save fuel as well as brake pads/rotors.
Coasting in neatral saves more fuel than coasting in gear. You can coast farther in neutral. If you are going to coast a given distance in neutral, it takes less speed than coasting the same distance with the engine draging.
LT4 VETTE
Dodging 18 wheelers between Tennesse and Virginia was an experience, I have many new gray hairs to prove it! The 51.1 MPG was recorded using Amoco (BP?) regular gas, coasting whenever possible, tires pumped up to 35 psi, new air filter. Last time I tried this, I only got a 48.4 MPG avg. Having said all this, I don't recommend doing 55! With the rising gas prices, I expect to see 55 MPH caravans to save fuel.That is if you don't have 1,600 miles to drive....it would seem to take forever!
Dodging 18 wheelers between Tennesse and Virginia was an experience, I have many new gray hairs to prove it! The 51.1 MPG was recorded using Amoco (BP?) regular gas, coasting whenever possible, tires pumped up to 35 psi, new air filter. Last time I tried this, I only got a 48.4 MPG avg. Having said all this, I don't recommend doing 55! With the rising gas prices, I expect to see 55 MPH caravans to save fuel.That is if you don't have 1,600 miles to drive....it would seem to take forever!
It really isn't that bad to cut your speed a little and save a lot of gas. I drive 3 to 4 times a year down to Fl 1170 miles.
By limiting my speed to 65 mph it only adds about 45 minutes to my trip. I probably average about 62.5 mph on the way down and back. Just think if you don't have to make that one last fuel stop due to the fuel savings. Your saving 10 minutes right there alone. I save 6.4 gallons of fuel round trip. It may not sound like much but it is still 6.4 gallons of fuel or $18.50. By adding 4 mpg to the fuel mileage in my 87 I no longer had to stop for fuel 100 miles from my destination. At least the 97 has a 21.2 gallon tank vs the old one with a 15.8 gallon tank. Now if I could just get 2.5 mpg more or 30 mpg I'd only have to stop once for fuel on this trip.
BTW I'm working on it.
Mitch,
Your driving habits use the EXACT same gas-saving strategy I do when traffic is light.
When traffic gets a little heavier, I just set my cruise to 55 (in a 65 zone) in the interest of being nice to my fellow (impatient) man. Otherwise I bounce from 52 on the flats to 48 on the uphills and then up to 58 on the downhills. Past 58, even on downhills, I tend to waste more gas than I save due to wind resistance.
Gary,
I remember watching a "Food Lion" grocery store commercial where the CEO was bragging that they save us money by governing their fleet of OTR rigs to 53 MPH. It would have been around 1984 to 1988 that I remember this.
Was Food Lion unique back then? Did it have something to do with the old double nickel limit? Were rigs just weaker back then?
If my Scangauge cooked and did my dishes, I'd love it more than my wife.
By the way, my reading of some diesel tractor and boat reviews told me that a diesel makes 20 horsepower per gallon per hour.
I'm sure the numbers vary slightly, but I always like to imagine that my horsepower output tracks my GPH, so that 2 GPH, for example, is 40 horsepower and 3 GPH is 60.
I'm always amused when I'm cruising downhill at .7 GPH, and my engine is making less power than my mother-in-law's 15 horsepower riding mower.
Sometimes as a game I'll try driving on a mostly empty interstate and keeping the GPH at 1.5. Sometimes I'll be going 43 MPH up a hill, sometimes I'll be going 69 down the other side of that same hill.
I wonder if that wouldn't be the most efficient way to drive, barring the effects of traffic.
When traffic is very light and stop lights are far away, I'll do 42 in a 35 zone, even on city streets. I have determined my best gas mileage lives somewhere between a sustained 40 and a sustained 50 MPH.
"I drive 3 to 4 times a year down to Fl 1170 miles. By limiting my speed to 65 mph it only adds about 45 minutes to my trip."
Well, I did the math on this. 1170 mi. divided by 65 mph equals 18 hours. 1170 miles divided by 68 mph equals 17.2 hours. 1170 miles divided by 67 mph equals 17.4 hours. So, adding 45 minutes to the trip means you only decreased your speed from
67-68 mph to 65 mph, which to me is a negligible decrease. Any kind of a meaningful mph decrease would cost a lot of time. For example, going from 75 mph to 65 mph would increase your driving time by 2.4 hours (1170 mi. divided by 75 mph equals
15.6 hours).
My wife and I drive, on vacation, from Helena, Montana, to Minneapolis (and of course back) almost every year. Back in the days of that horrid 55 mph speed limit on the freeways, the math was 1078 mi. divided by 55 mph equals 19.6 hours. Now we drive at 80 mph, with the math being 1078 mi. divided by 80 mph equals 13.4 hours. That's a considerable time saving. Anyone who drives long stretches of freeway in places North Dakota and eastern Montana knows how boring the scenery is and that at anything under 70 mph it seems like you're crawling. We about went nuts driving that route at 55 mph.
Someone correct me if I'm wrong. I'm not too good at math.
Well, I did the math on this. 1170 mi. divided by 65 mph equals 18 hours. 1170 miles divided by 68 mph equals 17.2 hours. 1170 miles divided by 67 mph equals 17.4 hours. So, adding 45 minutes to the trip means you only decreased your speed from
67-68 mph to 65 mph, which to me is a negligible decrease. Any kind of a meaningful mph decrease would cost a lot of time. For example, going from 75 mph to 65 mph would increase your driving time by 2.4 hours (1170 mi. divided by 75 mph equals
15.6 hours).
My wife and I drive, on vacation, from Helena, Montana, to Minneapolis (and of course back) almost every year. Back in the days of that horrid 55 mph speed limit on the freeways, the math was 1078 mi. divided by 55 mph equals 19.6 hours. Now we drive at 80 mph, with the math being 1078 mi. divided by 80 mph equals 13.4 hours. That's a considerable time saving. Anyone who drives long stretches of freeway in places North Dakota and eastern Montana knows how boring the scenery is and that at anything under 70 mph it seems like you're crawling. We about went nuts driving that route at 55 mph.
Someone correct me if I'm wrong. I'm not too good at math.
I'm not saying to cut your speed 15 mph for the whole trip. Heck my family would never see me if I had to drive 55 mph all the way down. I have a Valentine 1 in the car for the 55 and 60 mph zones. That is where I make up time during the trip. There is a pretty big savings running 5 under the 70 mph speed limit. There is almost zero savings in gas running under 60 mph in my 97 960 Volvo. The difference between 60 and 65 is between 1/2 and 3/4ths of mpg. So you can understand that running much slower than 65 is not economically feasible as far as time goes.
I hate to admit it, but I have my own simple answer to help "wake them up".....I call it the "Phantom Left Turn Signal".quote:
Originally posted by ekpolk:
I encountered at least a half-dozen such mow-rons last night. I'm cruising along at ~72mph, in the right lane of course, left lane wide open. Sure enough, they come roaring up right behind me, slowing to avoid plowing through me. Then, and only then, do they jerk over to the left lane and pass, engine roaring at redline. I guess some folks think slower traffic is supposed to move into the breakdown lane so they can speed on by. That whole smooth lane change thing is just so difficult to perform -- you actually have to move your wrists a couple times. Amazing.
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