Deteriorating gas mileage is one of those problems that you may encounter as a vehicle owner. But does it mean that age is catching up with your Volvo or Mercedes? Is there something you can do to remedy this?
Leading Causes of Poor Fuel Economy
Dirty fuel injectors and air filters are among the major causes of poor fuel economy. Deposits of carbon inside the injectors can inhibit the delivery of healthy fuel doses. As a result, this can cause a waste of fuel and misfiring.
Fuel injector cleaners can do the trick if the problem is the clogged injectors. If that doesn’t work, you can go for professional cleaning of the fuel injectors, or even a replacement if necessary.
On the other hand, a dirty air filter can choke the engine of air. The result is a reduced fuel economy because of unbalanced combustion. Check the air filter and replace it if it is too dirty.
Another cause is slipping transmission or clutch. This can happen for both manual and automatic transmission. If this is the case, it means that the engine cannot effectively reach the wheels, and the fuel economy deteriorates.
Without a doubt, engine misfires are fuel wasting, and the culprit for this may be dirty or worn spark plugs. Iridium and platinum plugs can go for up to 100,000 miles. Unfortunately, stop and go driving or short trips can cause spark plug fouling. Inspect the spark plugs and clean them if necessary. You can install a new set of spark plugs to be sure.
But engine misfiring can also come from other fuel and ignition system problems. For example, it can be weak ignition coils, or even vacuum manifold leaks. Low fuel pressure can also be the leading cause of poor fuel economy.
Also, If you tend to use a higher viscosity motor oil, the fuel efficiency of your motor vehicle will suffer. Some vehicle manufacturers tend to mention the recommended viscosity, and it’s best to stick with it.