When gas prices escalate, like the past few weeks, people always start to ask the question, do I REALLY have to put premium fuel in my car? It is a legitimate question, especially when you look in the ownerís manual or open your gas flap and it says in large letters, PREMIUM FUEL ONLY, what should you do?
For most people, burning premium gas is not required, but recommended. There is a reason your carmaker recommends premium, and itís not because they are in cahoots with ExxonMobil. The simple facts are that testing determined your car runs at maximum efficiency on premium fuel.
Knowing that premium fuel is how your car runs most efficiently means that you will have the maximum in acceleration and top speeds. It also means your car will get the best fuel economy when running on premium. You can suffer a loss of 10% in fuel economy, or sometimes more, by dropping down to regular unleaded. Even at that, with the spread of gas prices being so large between regular and premium, you will save money running regular fuel.
Be aware that making a switch to regular fuel is not for everyone. I do not recommend it for people with high-performance engines, like a Porsche or a Corvette. I do not recommend switching if you are pulling or hauling a heavy load, and I do not recommend it for cars more than 10 years old. Over the last decade, carsí computers have gotten smart enough to adjust themselves to a lower octane fuel and not cause the pinging we used to have to go through. If you go from premium to regular fuel and you do get a ping, I suggest you go back to premium to be on the safe side.
I tend to err on the side of caution when it comes to your carís engine, so I donít recommend using regular fuel if you have a turbocharger or supercharger. Some will say it is fine, but it makes me uncomfortable. If you are not sure what your manufacturer recommends, take a minute and look it up in your manual or look on the governmentís website, . You just canít assume anything with a car, a Smart Fortwo microcar calls for premium fuel in their 3-cylinder engine. Go figure.
If you are still on the fence on this subject, I recommend you fill up with a tank of premium fuel and document your starting mileage. Run the tank as near empty as you safely can, then fill up again with regular fuel and see what the fuel economy difference is and how your car performed. If the drop in fuel economy is not substantial, and the car performs well, stay with the regular, you wonít hurt a thing.
For most drivers, switching to regular from premium is not going to substantially change your financial situation. A 15,000 mile per year driver averaging 20 miles per gallon will save $31 per month dropping premium fuel at a 50 cent per gallon higher price. That assumes no drop in the overall fuel economy. Most cars will drop a little in fuel economy, so the savings may actually be less. I have tested cars using both regular and premium fuel and have seen some that showed no drop in fuel economy.
Keep in mind that premium fuel has more ethanol than regular fuel does, and it is a fact that ethanol hurts your fuel economy. My conclusion is if your vehicle does not ping when using regular fuel, use it.