if a car manufacturer says to use premium fuel, would using regular fuel cause harm or just lower performance?

Question

Manufacturer of some new cars tell you to use premium fuel. Sometimes they state that using regular might harm the engine. I had always thought that you could use regular fuel instead and the only difference might be lower performance.

Answer 1

This is an important question in light of the escalating prices at the fuel pump and the temptation for many to go to the cheaper regular fuel in spite of the fact that their owner's manual recommends premium.

HERE ARE THE FACTS:
In most of the U.S., regular gas has an octane rating of 87, midgrade gas is 89, and premium is 91 or 92.

The octane rating doesn't indicate how much power the fuel delivers; all grades of gasoline contain roughly the same amount of heat energy. Rather, a higher octane rating means the fuel is less likely to cause your engine to knock or ping.

Knocking is caused by uneven combustion in the cylinder. You need a gasoline with a sufficient octane rating to
prevent this knocking in your car's engine.

Higher-performance cars often require midgrade or premium gas because their engines are designed for higher compression (higher compression = more power), and regular gas may cause knock. If your car needs high-octane gas, the manual will say so and you should use only the recommended grade of gas.

On the other hand, using high-octane gas in a car designed for regular accomplishes little except more rapid combustion of your money. Engines designed for regular fuel don't improve on premium and sometimes run worse.

Answer 2

some cars tend to work alot better with a higher octane of fuel,and some get better fuel economy even though they pay more for it.
if a vehicle calls for premium fuel usually the fuel filler neck has a smaller opening as the regular will not fit as it is bigger.
mainly this is only seen in newer vehicles.
if you do use reg in a vehicle that requires premium ,,it will spark knock and make some pinging noises under your hood
and could set off you service engine light.

Answer 3

If your hand book specification calls for 93 octane it's there for a reason, compression and combustion chamber shape . Both reasons combine for their listed recommendation.

If you use "NO" octane fuel the anti knock sensor constantly retards the spark to prevent pre-ignition. The combustion temperatures go through the roof which sooner or later ruins valves pistons and compression rings and scores cylinder walls.

If you payed money for a car requiring 93 octane gas why do you think about "chincing out" buying shi**y gas.

Answer 4

The answer is yes. Toyota is the worst, they advertise so many horsepower and then in fine print with prem fuel. The answer is yes Toyota and Nissan are some of the worst. The cheap gas WILL cause a ping or knock and the performance will drop.

Answer 5

The ONLY difference is the engine might knock. Also known as 'ping' or predetonation.

Answer 6

and preignition means pistons are being eaten away a little at a time. also you will lose gas mileage can be as high as 5 mpg on some cars.