Does it really matter if you don't use high octane fuel in a turbo engine?

Question

I own a Jetta 1.8l turbo engine. I've heard that it doesn't really matter whether or not I use high octane gasoline, so long as I use only one type of gasoline consistently. Is there a scientific basis for this?

Answer 1

Turbocharged engines produce more heat and have higher combustion pressures. High octane gas reduces detonation caused by high temperatures in the combustion chambers.

If you use a lower grade than recommended, either you will get detonation which damages your engine or your cars computer will retard timing to prevent it and you will lose power.

Answer 2

Turbo engines need higher octane. It is true that turbo engines have a the compression ratio lowered, but that does not mean you can get away with lower octane. It has lower compression because the turbo more than makes up for the lowered copression. Once the turbo is spooled up, you're cramming more and more fuel/air mixture into the cylinders. With the higher and higher cylinder temperatures generated with a turbo, I don't see how you think you can get away with lower octane.



Do not listen to those mechanics! (They earn money when you break connecting rods)

Answer 3

You can use the cheaper regular gasoline if you are doing consistent speed driving such as on a long highway trip or around town as long as you do not accelerate rapidly all the time. It would be best to use high octane fuel for driving in the mountains for instance, or if you like to put it the mat everytime you stop. Using regular will affect your performance and fuel milage under those conditions, you may also notice knocking and pinging noises coming from your engine while under stress and using regular unleaded fuel. Hope this helps.

Answer 4

It should state what octane to use in the owner's manual.
If the car calls for 91 or 94 octane I strongly recommend using it for the sake of $0.10.
After a while, the car will PING. (You will hear pinging in the motor)
Besides a Jetta gets awesome gas mileage anyway so it's not like driving an SUV at 10 miles to the gallon

Answer 5

The only thing I know is you should use what the manufacture recommends, I know cars with superchargers need premium fuel but I.m not sure about turbocharged cars, I had a 83 thunderbird turbo coupe and I don't think that it took premium gas, I don't remember, that was a long time ago.

Answer 6

Dodge man is correct. Turbo engines use lower compression pistons that require less octane and are less likely to knock.

Answer 7

For a car with a turbo it is optimal to use a gasoline with an octane above 91. this will keep your injectors clean which is necessary to make the car last longer and get better gas mileage

Answer 8

you heard right, its not going to make much of a difference in what grade of fuel you use in it,i i have a customer that had an older dodge that has a turbo on it,and he runs a cheaper grade in it ,and all the times i have drove it ,it seemed to run really good,buying a higher costing fuel wont make it run any better,it will just cost you more,that s about it,good luck, i hope this help,s.

Answer 9

you can safely use any octane level as long as the engine does not spark knock when it spark knocks you have to increase your octane

Answer 10

Use what the manufacturer tells you to. They tell you to use a specific kind for a reason.