thinking....

so i was coming out of the drivetest centre and i saw a pamphlet that said "if you drive at 100 instead of 120, you will use 20% less fuel" and i was struck by the facetiousness of that statement.

fuel consumption cannot be linear - at no point, EVER, will your engine be operating while burning no fuel. can't be done. therefore, it can't be true that if you're driving at 50, you're burning half as much fuel than if you were driving at 100. i drive slowly - usually 10 under the limit - not only because my car is a piece of shit but also because i'm cheeeeeeeeeeap and do everything i can to save every last drop of fuel:

- i take my foot off the accelerator when going down long hills
- i keep all my windows shut (reduces drag)
- i don't have stupid things like flags waving out the windows (that can up your fuel consumption by 5 to 15%!)
- i drive slowly - the less work my car does pushing against the air, the less fuel it burns
- i even shut the car off in drive-throughs unless i'm going straight on through. if i'm going to be waiting more than 60secs, off it goes. and then i sit there until the way to the speakerphone is clear and i just drive straight up. i don't care that there's fifteen cars lined up behind me - moving up four feet at a time isn't going to get them there any faster. if they were smart, they'd shut their cars off too.

so anyway, the thing is that there has to be a bottom line fuel consumption - let's called it the fixed cost. this is the rock-bottom amount the car needs to get going.

then there'd be the variable cost, which corresponds to the demand being made on the car - the faster the car goes, the steeper the incline, the heavier the load or the drag, the faster the wind speed, the more fuel the car will burn.

instead of the graph of fuel consumption being a straight line from zero to whatever, therefore, the graph would start somewhere above zero and then swoop upward in an increasingly steep curve.


so there.

and it's not called a "parking brake" - i argued with the drivetest examiner today about that. it's a "hand brake", required by the highway traffic act to be present as an emergency backup braking system in case, i dunno, the brake lines explode or the master cylinder goes "pop!".

so now you know - go fix yours.