Fuel Economy Techniques

[quote=“sulavaca”]If you use a smart phone then you can purchase a blue tooth OBD2 connector such as OBDkey and plug that into many models of car. An app called Torque can be installed onto many phones and provides a live fuel economy update to your mobile.
I have tried this with some success but it doesnt work with all Taiwan built models.[/quote]

Fab-gadget-tastic!

No direct use to me of course, since I’ve neither the smart phone nor anywhere to plug it in, my 1986 car being, for the most part blissfully, free of electronics.

Be interested in anyone elses results though.

I was kind of assuming that many modern cars would be so instrumented out of the box, but I don’t really know much about modern cars.

Actually most modern cars don’t offer much in terms of a fuel economy meter.
I remember when BMWs had the “economy” gauge in the instrument panel. :laughing:
It was purely an engine vacuum gauge which would just go up and down so wildly, and provide no accurate measure whatsoever. It was always fun though to see it bobbing up and down so wildly though. I believe they actually fitted that useless superfluous addition for around ten years. It’s gone now of course.

These days the manufacturers tend to offer fuel economy results after the fact, which means that they are far more accurate, albeit too late, as the driver has already spent the fuel by the time they get the results.

There are some more useful examples perhaps in a few of the hybrid and electric cars which offer realtime information based on a host of inputs and equations.
It would be nice to see this embedded into more modern vehicles though, as its a very useful addition as you say.
Still, the issue again with even the hybrid and electric models which offer a live feed, is that they are only so accurate. As it was mentioned earlier in the thread, using quite a lot of power output to get up to cruising speed more quickly, actually can result in greater fuel economy. Even the most modern of fuel economy meters don’t work in this scenario, as they aren’t predictive. This means that they would all give a poor economy reading while you were performing this action, and many drivers would think to back off the throttle as a result. It would only be after the fact, and on the five minute economy scale, that the saving would be shown, but then again, the driver might not understand after a five minute delay in the economy result, where the resulting saving came from.
So again, in this sense, even a live fuel economy gauge would be as useless as the old BMW engine vacuum gauge, which was phased out.

Yeh, that Mk1 Honda Insight seems to be pretty well instrumented in that regard.

Probably just as well it wasn’t (AFAIK) available in Taiwan, since obsessing about a dashboard meter is inadvisable on these mean streets.

I imagine all-aluminium bodywork would be expensive to unbend, if you could find someone here that could do it.

Accelerating and climbing to a cruising speed and altitude in aircraft is standard practice. The fuel used to climb quickly and attain cruising speed is offset by being within the cruising parameters for longer. Of course, with aircraft it is different because aircraft make use of the less dense atmosphere to save fuel - but the principle is roughly the same, especially concerning speed - using fuel to accelerate in order to spend longer and travel further in a cruising profile actually saves fuel.

[quote=“Abacus”]
Overall I dislike several of the suggestions on the website. They’re either dangerous or downright obnoxious to the normal flow of traffic. Easy on the gas and brake (in the city), drive the speed limit and keep the vehicle maintained (esp tire pressure).[/quote]

Slipstreaming could easily be dangerous, for obvious reasons, though at the vehicle separations that seem to be “normal” on the motorways here, I’d say it must be part of normal driving.

I’m not sure how far behind a truck you have to be before you lose all benefit. Of course relatively few cars drive at truck speeds (itself a benefit) anyway, but I do, so it’d be nice if I was getting some slipstream benefit as well.

I’m not sure how dangerous “surfing” is. The main downsides I can see are that you are in the trucks overtaking path (so you’d have to be ready to get out of his way) and you and the truck are probably obstructing two lanes, ditto. Sounds maybe more stress than its worth, though I might have a cautious experiment sometime.

“downright obnoxious to the normal flow of traffic.” pretty much covers any safe or economical driving, since “normal” drivers are idiots. One good way to ensure you’re “Easy on the gas and brake” (though the news is apparently that the first may not always be optimal) is to keep a big gap between you and the traffic in front, but this will enrage the idiot drivers behind you and so may cause an accident.

[quote=“Ducked”][quote=“Abacus”]
Overall I dislike several of the suggestions on the website. They’re either dangerous or downright obnoxious to the normal flow of traffic. Easy on the gas and brake (in the city), drive the speed limit and keep the vehicle maintained (esp tire pressure).[/quote]

Slipstreaming could easily be dangerous, for obvious reasons, though at the vehicle separations that seem to be “normal” on the motorways here, I’d say it must be part of normal driving.

I’m not sure how far behind a truck you have to be before you lose all benefit. Of course relatively few cars drive at truck speeds (itself a benefit) anyway, but I do, so it’d be nice if I was getting some slipstream benefit as well.

I’m not sure how dangerous “surfing” is. The main downsides I can see are that you are in the trucks overtaking path (so you’d have to be ready to get out of his way) and you and the truck are probably obstructing two lanes, ditto. Sounds maybe more stress than its worth, though I might have a cautious experiment sometime.

“downright obnoxious to the normal flow of traffic.” pretty much covers any safe or economical driving, since “normal” drivers are idiots. One good way to ensure you’re “Easy on the gas and brake” (though the news is apparently that the first may not always be optimal) is to keep a big gap between you and the traffic in front, but this will enrage the idiot drivers behind you and so may cause an accident.[/quote]

I’ve done slipstreaming or drafting before to save mileage but I gave up after 5-10 miles. It’s not enjoyable and nerve wrecking because you have to be close to get a noticeable benefit. Several things really suck about this. For one you can’t see pretty much anything in front of you. This could include traffic work or obstacles such as lawnmowers or ladders (seen both on freeways). You are going to have zero chance to avoid this. Drafting also sucks because I prefer to use cruise control and trucks typically don’t maintain a constant speed esp if there are inclines.

Surfing would just be infuriating to be following since you be blocking 2 lanes and trucks frequently drive below the speed limit.

I don’t know what you read into easy on the brake and easy on the gas. I’m not implying leaving a 30 car following distance and coasting from 1/2 km to a red light. You would be surprised at how many people are accelerating and then immediately switch to the brake.

When riding uber-long distances (on my Ducati) in Australia i would regularly slipstream big trucks. Save 50-80% of the fuel.

You’d have to sit n the center of the windfield, about 6-10 feet behind, and always cover the brakes. But you could always outbrake a semi-trailer doing 120 in a 100 zone if you kept watching the brake lights.

Of course there was the risk of falling asleep, but I had a nice big tank bag to lie on. Far less wind buffeting, far less noise, far less fuel used and throttle pressure needed, and no danger of a head on collision.

Those pro drivers really really know just how fast to go where, where the cops are, and seem to keep an amazingly constant high speed over awesome distances (1000 km or so, though i had to refuel every 300 - 350 km. Normal range was less than 160, so that’s not bad).

Slipstreaming was my most effective hypermiling technique.

Very interesting. Und also very scary.

6ft !!!???

If you tell me “you could always outbrake a semi-trailer doing 120 in a 100 zone if you kept watching the brake lights.” I’m inclined to believe you, since you had a very good reason to verify this.

But I’m very, very surprised.