Why would a car require premium grade fuel?

Question

I was on Kelley Blue Book, and I descovered the brand new Mercedes Benz Fortwo. (its on the home page [kbb.com) after reading their review it said that the engine required premium gas. Why?/ does it really matter? (I really want to buy this car and this will probably be the deciding factor)

Answer 1

some engines require higher fuel rating the cars i often drive always require this,in the past i switched to the cheaper fuel and  it caused an arm full of problems.

When i went to a garage to get the car fix they gave me a lecture about the engines being made to run on that fuel and with anything in life no matter what anyone says if you fill it with the wrong stuff it maybe fine or seem fine but you can't run things on the wrong stuff,which is a fair comment.

All the engine running is designed for that fuel so no matter what anyone does say on here it etc its not worth the risk to save a few pennies at the pumps.

Answer 2

Performance over all..

If a motor is built and designed for higher Octane fuel means it can perform and get better mileage using a Higher Octane

Also might get its best milage Using the Higher Octane.

Side note ,,,, If you use Lower Octane fuel in the car Might make it get worse mileage over all and not perform as needed. Also gets worse over time using Lower Octane rated fuel.

Answer 3

If you think you can afford to run a mercedes why are you worrying about fuel?

Different countries have different grades of fuel, for instance USA fuel is pants (like UK 2 star or worse) UK fuel is pretty good, but available in 2 grades, Japanese fuel is sometimes referred to as rocket fuel - think how many j*p performance cars are available all over the world.

Just put the best you can get into a performance car and the cheapest into your eurobox!

Answer 4

High compression engine require high octane (resistance to self ignition) gas.

As simple as that.

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Modern cars come equipped with engine knock sensor.  In that case you might be able to run regular gas even if you are required to use super / premium gas.

The guy below is correct about using the wrong gas - in the long past.  It is NOT true anymore.  In fact some car makers are switching the recommendation just because it is difficult to sell cars that use premium - knowing that the engine knock sensors will prevent damage - at the risk of losing performance.

Of course there's an exception.  Turbo engines ALWAYS require premium gas.

Good Luck...

Answer 5

Because that's what it was engineered to run on. You get better performance from premium fuel. Yes it really does matter. Only the people without a clue will tell you other wise.And if you can afford a new Mercedes the price of fuel should not be a problem for you.