w00t! 36+ mpg wagon!

Myth busters did an episode on drafting... long, long time ago.

The basic finding was that you had to be EXTREMELY close to benefit from riding behind trucks.

If you weren't EXTREMELY close, then you actually lost mileage as a result of the turbulence and down-force winds coming immediately off the back of the trailer.

I'd guess that their test speeds were 60-70mph... but don't at all remember.

Okay here's the episode...

http://en.wikipedia.org/wiki/MythBusters_(2007_season)#Drafting_For_Money

2-3 seconds at highway speeds BTW is a long distance. There are 3600 seconds in an hour. There are 5280 feet in a mile. If traveling 70 miles miles or 369,600 ft in an hour or 3600 seconds, then that's 103 ft per second.

2-3 seconds behind a *stationary* object would be 206 ft away.

Also keep in mind that trucks with no load and good tires, can stop pretty damned quickly.

As a general rule, I back-off enough to be able to see around vehicles. Sometimes I'm on the brakes before they are.

Not sure what mythbusters episode you saw, But there is an episode that says at 100 feet from semi at 55 mph you can get 11% MPG improvement.


http://www.youtube.com/watch?v=lttgT1XZVvE

11% or 8% ?

http://green.autoblog.com/2007/10/2...g-10-feet-behind-a-big-rig-will-improve-mile/

Is that worth the risk ? 3/4 of all fatal accidents involving big-rigs are caused by the driver of the vehicle. (actually would've thought it higher)

EDIT: That's 11%. (monitor) 30 mpg turns into 33.3 mpg.

The way I noticed the difference was when I was using the Scan Gauge if a truck would pass me I'd immediately notice the MPG reading on the Scan Gauge go up and it would remain higher until the truck would get a few hundred feet in front of me then the mileage would drop back down. As for engine off coasting, I've tryed it a few times on my '88 Escort Pony and haven't seen any benefit from it. I think the reason for that is because most cars made since the mid or late '80's have deceleration fuel cut off which cuts the injectors off during deceleration until the engine speed drops to a certain RPM, which I think is somewhere in the 1000-1100 RPM range.

My Escort has this. When I take my foot off the gas and the car is in gear (5 speed) my Scangauge says the injectors turn off. However, the engine is still spinning a dead weight which slows you down unless you are going downhill. If you were to turn the engine off and put the car in neutral you would not have the drag of the engine and you would be using no gas so, better MPG. The gain you get would depend on the amount of time you can coast with the engine off. If you only do it for a few 1/8 mile stretches then don't expect much but if you can do it for more distance, say a mile or more at a time, you should notice an improvement. Your not noticing an improvement my have to do with your Escort's CFI style fuel injection system, it may use more fuel to start the car then you saved coasting compared to the more modern MPFI used on the newer Escorts and 1st gen GT's.

You ever notice how cars, particular the smaller ones, get pushed-off to the side when moving past the front-end of trucks ? Or perhaps your own as you pass them ?

Slightly off-topic, but I suspect this is the "surge" they're referring to in the Toyota vehicles. 5-speed manual but have noticed what could be described as a brief surge when decelerating down toward/in that range and in-gear. That's just the computer assisting the throttle. http://www.msnbc.msn.com/id/35493316/ns ... gton_post/

That entire Toyota gas pedal thing is so retarded. Toyota is crying like a little baby and has no idea what to do. It ain't that hard people! It shouldn't take more than 2 weeks to come up with a fix for a stupid problem like this.

Here is my advice:
First off, don't issue a recall when you don't have a solution to the problem because it will turn off those who own you product.

If its the computer making it surge, reprogram it.
If the gas pedal catches on the carpet, make it shorter.
If the assembly itself it sticking, find out why and make a design change.
Or do like the American companies do. Refuse to acknowledge there is a problem. Meanwhile, quietly redesign the offending part and phase out the old one. If somebody complains to a dealer about the problem, replace the part with the redesigned one and charge an arm and a leg.

It ain't that hard.

Hehehe....

There are about three different separate issues. The gas pedal being too long is one. Something about the brake is two. They've admitted to both.

The latest is the "surge" which 3rd-parties (mostly gold-diggers) are trying to confuse with the gas pedal; claiming that this is the real reason for the acceleration problems. THe author in the linked article tries to say that this otherwise normal surge, likely experienced during deceleration is an indication or warning sign of "the problem". Toyota meanwhile hasn't admitted to any real problem with the ECU, saying that it was reprogrammed for comfort reasons; but otherwise never posed any safety related issues. (last I heard earlier in the week anyway)

The Scangauge only works with cars that have OBDII, in other words 96 and later with a few exceptions.

I think it would be interesting to find out if the OBDI Escorts turn off their injectors. I also don't like the new "fly-by-wire" throttles alot of these new cars have. Electric motors burn out, switches wear out, it sounds expensive if things wear out. Not to mention what happens when the car is so old that the manufacture no longer makes parts for it.

I know the '88 does, because I remember seeing something in the owners manual a couple years ago when I was looking at the fuse box diagram and one of the fuses said something along these lines. (fuel cut off or injector cut off) I'll have to look it up again and see just how it was labeled and post it later on.

The results will be the same with the exception of possibly the injectors coming back on at a different speed/rpm. Nearly all cars since some time in the '80's manual or automatic transmission have DFCO. (deceleration fuel cut off)

the best i get was driving 190 trip going 55-65 for the first 170 miles and 90 the last 20 i ended up with 35.9 mph total, out of a 93 auto wagon

the best i get was driving 190 trip going 55-65 for the first 170 miles and 90 the last 20 i ended up with 35.9 mph total, out of a 93 auto wagon

Although I've been really slacking lately, I like to bike. Windy days make a HUGE difference. Shedding frame weight makes some difference. Shedding backpack weight, seemingly makes no difference. Shedding wheel weight makes the most difference. Maintaining tire pressure has a huge impact as well. On the hilly terrain of the Ohio Valley, could ride for tens of miles without tiring. BUT, on occasion I'd have my Niece and Nephews join me on trails but they would frequently like to stop. Strangely, I found that that stop and go, stop and go would actually tire me out. So I well understand how stop and go, and slow traffic can really harm mpg.

Keeping that point in mind...
It has always bugged me, really irked me how poorly many municipalities manage the timing of their traffic signals. Moving along a main road, it's not uncommon to literally go from light to light, letting out a car or two, if any, from light to light. If you (carefully) treat just one of these lights as a stop sign, or rapidly accelerate and (safely) manage 15+ beyond the speed-limit to beat the next light, you can then continue on unimpeded. Personally wouldn't mind sitting at a light for some extra time at a side-street, if it means that i can keep moving once on the main road. But having to choose between driving at 20-30mph under the posted limit, or sitting at each light for a time, is asinine, and aggravating.

Many years ago I calculated mileage (on a leaky headgasket, cracked head) and came up with 32mph. Ran cool then. Typical driving circumstance was ramp up to 60mph for 30-60 seconds and stop. Highway speeds, but there were still frequent stop lights. (poor traffic management)

Don't recall the exact number, but calculated mileage earlier this year (warmer weather) and came up between around 30, 32mph. Thermostat bypass valve is bad so runs cold. Mix of suburban city, highway. Normal silver-foot driving. (little less dense than lead) I like 79+mph driving.

Based on unscientific observation/experience, (without actually calculating,) it seems like a dirty MAF/ACT made it run lean. Didn't matter how lead-footed I drove, mileage seemed consistent. Cleaned them and my mileage seemed to decrease. Seems like a spent heated-O2 can allow it to run rich. When it got cool out, it was as though someone were stealing my gas! Replaced the ~250k mile Motorcraft sensor with another Motorcraft, and mileage returned to expected normals by 1.5 tanks down the road.