Improving mileage - not that hard after all
July 28th, 2008 Roshan
I’ve been driving around for more than a year now, and while petrol prices weren’t bad enough to cause a problem six months ago, at Rs. 55+ per litre now it’s like I cut a hole at the bottom of my wallet every time I visit a petrol bunk. Naturally, all those articles about hypermiling caught my attention, but it seemed like a lot of work. I gave it a half-hearted shot anyway, and saw my mileage go to 16.5 km/litre, up from the 13 km/litre I was getting before. The car is an 11-year old Maruthi 800 that’s second hand, and that’s gone through 45,000 kilometres. A little more effort and I’m now up to 19 km/litre now, a number neither my parents nor my friends believe. But that’s because no one else has given it a shot, it’s near second nature to me now to drive like this.
For 16.5 on this car:
- Drive at a regular 45 km/h when the traffic allows. No faster than that, and some times at 40 km/h.
- Keep the car in the low revs without letting the engine lug. This means shift up earlier, so that you’re in the highest gear possible without letting the engine lug.
- Don’t get stuck in stop-and-go situations, idle or kill the engine (if it’s really bad and you don’t see any two-wheelers around) and wait till enough space opens up before you move.
- Don’t slow down for two-wheelers who try to edge into your lane in the left. Blast the horn at them, overtaking from the left is illegal and you’re in the right for giving them a scare. Don’t rev the engine though, wastes petrol. Actually, be careful here, two-wheeler drivers usually swerve in and out and while it is illegal for them to do this from the left, it’s not worth the fuel savings to hit them because if they get hurt you’ll have to take them to the hospital. If you’re on your way to a hospital anyway, then it doesn’t matter, go ahead.
- Switch off the engine if the signal timer shows more than 20 seconds. This also depends on where you are in the line. I add one second per car from the stop line to calculate, and generally only start the vehicle once the car ahead of the one immediately in front of me starts.
- On ‘green corridor’ roads, going faster than 45 km/h is actually better because although they claim to be optimised for 40 km/h, that doesn’t take into account the time to accelerate (which is longer than you may think because of the two-wheelers and autos that fill the roads).
- On roads like the OMR and Mount Road, you can switch off the engine (careful to keep the key in the standby position, so your signal lights will show and you still have control over the wheel) but be careful because if you turn the key fully the steering wheel locks.
For 19+:
- Know your route. Seriously, analysing your route can help incredibly. I’ve memorised signal timings for the few signals which don’t have timers along the routes I commonly take. Sometimes the signal will change midway through the timer (if it’s a right signal like at the Velachery Bypass) so knowing when that happens helps. For me, it’s fun finding the best possible mileage, like a high score on a video game.
- Again, know your route. Average traffic at the next turn, how the road is right after that, these are important things. Coming up the road to velachery that leads on to Sardar Patel Road, I usually shift to neutral 20m before the road narrows from 3 lanes to two. At 40+ km/h I’ll be running slightly lower than 30 km/h when I take the turn, allowing me to shift directly into 3rd gear nearly perfectly.
- Take the widest turn possible, this is usually the one furthest away from the pavement meaning there’s no chance that you’ll have to stop for a stationary vehicle parked at the corner, a pedestrian, or a roadside vendor. There’s also the added bonus that the road is usually smoother near the median and water doesn’t usually pool there so there’s no patchwork business.
- Following up to that, avoid flyovers when possible. Avoid stop-and-go traffic on a flyover at all costs, lots of fuel spent there.
- Pay attention to the traffic, often you can spot a red brake light six cars down the line that’s going to propagate, gearing to neutral means you won’t have to brake when it happens.
- Allow cars to pass you, move aside if possible and if you’re travelling slower than the average on the road ensure there isn’t someone doing the same thing next to you. That way people can overtake you easily. Besides being good manners, this has the much more important effect of preventing the other vehicle from making a bad effort at overtaking you resulting in both cars forming an arrowhead that requires braking and one giving way. You may be in the right, but hydrocarbons burn anyway.
- When you can’t avoid a flyover or subway, accelerate on the downslope only if there is space at the end to take advantage of the speed. Allow the car to slow down at the entry of a subway to see what the story is at the other end. If it’s empty, accelerate enough to keep you going up the slope. It’s better that way than holding to an even speed up and down. Let yourself slow down on the upslope, it happens. Also in places like Spencer’s Plaza’s underground parking, stop at the bottom of the ramp a few metres from it, then go all the way up to the next flat surface and stop there.
- Keep fuel as low as possible in the tank. I generally have between half a tank and nearly nothing in there unless I’m driving long distance.
- For god’s sake drop your high beam, just do it. It’s not for use when there’s at least one person driving in the direction towards you.
When I did all of this, I never expected much of a result, but when I finally decided to measure how far I can go I got these results. They’re approximate because I calculate when the bar reaches the E mark on my car (the actual empty is a few notches underneath) but I fill up a little after that. Another possible error relates to the fact that the car only shows how much fuel I have when it’s on so vapour may make it look a little higher.
So I went to C.A.R.S India to fix my broken headlamp and while I was sitting there waiting for the mechanic, this guy next to me is writing down on a piece of paper the following:
Back door glass
CARS India
After the tech looks at my car and tells me how much it’ll cost and when they’ll have stock of the lamp I go back to my car, and after reversing out I look at the glass on the back door of a yellow Maruti Omni. It says, “BACK DOOR GLASS” brightly on it. I would’ve taken a photo, but I was too busy laughing.
Update: Ha ha, 110 km on 5.45 litres, 219 on 10.9, that’s 20.1 km/l nearly. I’ve got air pressure to 28 psi in all the tyres instead of the rated 26 psi and I’m driving even more carefully now. Maybe I should try drafting, like Sido says.
Posted in Madras | 5 Comments »
Today I travelled by both the suburban 