Does turning off engine really save fuel or merely damage engine?
Kampala, Uganda | MOTORING GURU | After the cost of petrol inched closer to the Shs4000 a litre recently, many motorists are concentrating on fuel saving ways. Many are wondering whether it doesn’t make sense to turn off the engine when stuck in the ever thickening traffic jams.
Of course this is a silly question to people who drive newer cars and a no-brainer for those that drive the very ancient jalopies – those with carburetors. The newer cars have automatic systems that rapidly turn engines off when the car is stopped –even for a few seconds – and turn it on when the slightest pressure is applied to the accelerator. The carburetor oldies wouldn’t even consider killing the engine because it guzzles fuel when it restarts – according to some folklore, a restart consumes as much fuel as 30 minutes of idling!
Modern car engines are so efficient that restarting barely licks a drop of fuel. But does switching the engine off make sense even in the newer cars. Well, it depends on what you are aiming for.
Some experts claim that if you’re going to be stopped for more than 10 seconds, it’s best to shut off your engine. It’s however, mainly for environmental reasons.
But idling can waste fuel. Restarting tour 2.0 litre engine car uses as much fuel as idling for six seconds. So if you are idling in traffic at Clock Tower for 10 minutes, the nine minutes fifty four seconds is wasted fuel. But then again, how much is that in real money terms?
Well, your 2.0 litre car has been estimated to consume between 0.6 and one litre of fuel if it idles for one hour. That means each minute of idling costs you between Shs30 and 50. So 10 minutes idling in traffic is possibly costing you Shs300.
On the other hand, frequent restarting puts extra stress on your battery and ignition mechanisms. That could also cost you in maintenance fees – after say 10 years.
The point is this; in money terms, whether you idle or switch of your engine is not going to save you enough to pay your kid’s school fees. So consider other reasons for whatever you choose.
According to many experts, idling is bad for you car’s ventilation system and negatively affects the engine internals due to incomplete combustion (glazing of the combustion chamber, fouling of the spark plugs) which further decreases fuel efficiency for all other operations. What’s more, excessive idling affects other components (burning up of the catalytic converter, increased corrosion of exhaust system, increased engine wear due to higher vibration etc.), whose premature wear and replacement impact on your pocket.
There are some preventative measures to take so you lessen the chance of running into these issues:
• Get you oil changes more often than if you were driving normal, long, smooth trips
• Add a fuel injector cleaner to your gas tank every 3000 miles or so. This helps remove valve deposits and clogging, reducing the knocks and rattling noises.
• Switch to a higher octane fuel to reduce noise caused by the deposits clanging around.
Aside from your engine becoming damaged and aged prematurely, your brakes will also wear out prematurely. Check them often and have the brake fluid checked too.