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Which type of fuel do you use in your Cougar? Regular? Super Clean?

And if you use super clean can you tell the difference for performance/gas mileage/etc.?

I normally use regular (87 octane) but today i decided to splurge seeing how gas prices are so high i said [censored] what is 10 more cents a liter lol! I wonder if there will be a difference in anything?
 

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go back to regular!!! The engine was made to run on 87. Higher octane will yield you minimal gains at best. I'm sure someoen will chime in with the exact results, I can't remember them off hand, but they weren't good. :(
 

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We've been running Premium because that's what our New Beetle owner's manual tells us will give us the best performance with our 1.8 liter turbo. We're about to drop down to regular (87) because we don't race it, so we don't need performance, and we're about to take a trip in it, so saving the 20¢ per gallon will end up saving us around $20 on the trip.
 

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as long as your not pinging then using less than the manual says is ok. but if the manual says to use 87 and you run premium it wont help you at all. zero performance gain and it will actually make you lose performance. read up on what octane does, most people dont really know
 

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Originally posted by: monogodo
We've been running Premium because that's what our New Beetle owner's manual tells us will give us the best performance with our 1.8 liter turbo. We're about to drop down to regular (87) because we don't race it, so we don't need performance, and we're about to take a trip in it, so saving the 20¢ per gallon will end up saving us around $20 on the trip.
I don't think you want to do that. I pretty sure the reason for having to run the premium in the turbo is because of the turbo, well the heat, and pressure generated by it. 87 octane could cause tere to be detonation that could cause some serious problems.

But I not 100% sure on this maybe some one with more Knowledge could chime in.
 

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Originally posted by: Ronrazz
Originally posted by: monogodo
We've been running Premium because that's what our New Beetle owner's manual tells us will give us the best performance with our 1.8 liter turbo. We're about to drop down to regular (87) because we don't race it, so we don't need performance, and we're about to take a trip in it, so saving the 20¢ per gallon will end up saving us around $20 on the trip.
I don't think you want to do that. I pretty sure the reason for having to run the premium in the turbo is because of the turbo, well the heat, and pressure generated by it. 87 octane could cause tere to be detonation that could cause some serious problems.

But I not 100% sure on this maybe some one with more Knowledge could chime in.
My understanding is basically the same as yours ronno, so yeah . . . if the manufacturer tells you to run premium, you better suck it up and run premium. I mean . . . its $20 . . . is that worth the potential damage to your engine? I don't think it is.

I hate using even 91 octane in my car. 93 isn't rare, but its not super prevalent around here either. Neither of the gas stations in my town have 93, so if I'm ever bingo fuel when I'm leaving home, I'll put in like two gallons of the 91, just enough to get me where I'm going.

If you have a stock Cougar, don't waste your time or money on the higher grade gasoline - you're literally just lighting your money on fire when the higher octane gets combusted in your engine. And for the love of God, if you love your car, DO NOT USE ETHANOL IN IT. It will ruin your seals over the long run.
 

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Well, at the time we purchased the car, the dealer said regular was fine. We've also had contact with other 1.8T owners who run regular, and their cars are fine. Plus, the lable on the inside of the fuel door has both 87 & 93 octane listed (it's rather confusing).

We don't leave for a week, and my brother is checking with a friend who is a turbo engine mechanic instructor at the local college to see what the effects might be.
 

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Originally posted by: monogodo
Well, at the time we purchased the car, the dealer said regular was fine. We've also had contact with other 1.8T owners who run regular, and their cars are fine. Plus, the lable on the inside of the fuel door has both 87 & 93 octane listed (it's rather confusing).

We don't leave for a week, and my brother is checking with a friend who is a turbo engine mechanic instructor at the local college to see what the effects might be.
Hmmm, and I thought the Germans were supposed to be so smart . . . thats bizarre they have it dual listed.
 

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Premium in The Cobalt due to the supercharger. Straight from the manual. Although my manual says I can use 87 octane, it also says with 87 octane I will notice decreased acceleration. Doesn't say whether or not I would experience decreased gas milage though.
 

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Originally posted by: mercurycougar
Premium in The Cobalt due to the supercharger. Straight from the manual. Although my manual says I can use 87 octane, it also says with 87 octane I will notice decreased acceleration. Doesn't say whether or not I would experience decreased gas milage though.
i think that if you would lose any gas mileage at all you would make it up for the less you pay per gallon
 

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I know I get flamed for it, but I use Chevron 91 octane. I know I don't need it, but to me its one of those "piece of mind" things, knowing I'm putting the "good stuff" in. And with almost 125k miles, it seems like it helps clean up the inside of the engine. I did that with my old 1986 Honda Accord. When I got it, it ran like ass. After a few tanks of 91 octane and a couple bottles of Lucas injector cleaner, it ran a TON better. IDK, its just one of those personal preference things I guess.
 

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I'm not even going to flame you for the typo, thats too easy. I am, however, going to roll my eyes at the fact you ignore the manufacturer of your car, numerous scientific studies, as well as numerous personal experiences but members of the board who have demonstrated, repeatedly, why running 87 octane is the way to go on a stock Cougar.
 

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Originally posted by: KnappstamaN
Originally posted by: BigBalledOX
why running 87 octane is the way to go on a stock Cougar.
on a stock cougar.... so those of us with modified ones, it wouldnt hurt to give it the extra little umpf
No.

From NorCalCoug - and he's a Holy NECO reverand, as well as being pretty flippin smart

91 harms gas mileage in cars not made for it. I have to use 91 because I'm driving around a 3L/SVT Hybrid in an SVT contour. 11.25:1 compression is worthy of 91 + SVT timing (which already requires 91)
 

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Originally posted by: azbobbybooshay10
I know I get flamed for it, but I use Chevron 91 octane. I know I don't need it, but to me its one of those "piece of mind" things, knowing I'm putting the "good stuff" in. And with almost 125k miles, it seems like it helps clean up the inside of the engine. I did that with my old 1986 Honda Accord. When I got it, it ran like ass. After a few tanks of 91 octane and a couple bottles of Lucas injector cleaner, it ran a TON better. IDK, its just one of those personal preference things I guess.
There is no such think as the "good stuff". If you are thinking that 93 is "better" than 87, you are mistaken and you should read up on what octane ratings mean.
 

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HERE IS A LESSON IN WHAT OCTANE RATING MEANS

The octane rating of gasoline describes the ability of the gasoline to resist combustion. The higher the number, the higher the resistance.

This means that 91 octane is HARDER to burn than 87 octane. What does this mean for my car, you ask?

Even in modified cars, you should stick with the lowest possible octane rating of gasoline. Why? Because you want the gas to be as easy as possible to burn, without pinging. Pinging is pre-detonation, where the air/fuel mixture is igniting before it is supposed to.

The motor in your Cougar is a standard four-stroke internal combustion engine. It consists of the following sequence of events- suck, squish, bang, blow. First, you have the intake stroke (suck), where air/fuel is sucked into the cylinder. Then you have the compression stroke (squish) where the air and fuel is compressed in the cylinder to the point where it wants to explode because of the compression. Combined with a spark from your sparkplug and the compression in the cylinder, the air and fuel mixture is ignited during the combustion (bang) portion of the cycle. The piston is force downward by the force of the explosion, pushing on the crankshaft and rotating it. Then it compresses again to expel the exhaust gases from the combustion (blow)

A diesel motor works by compression alone! There is no spark plug. How do they do this? By high compression ratios. See, when the air/fuel mixture is squeezed enough, it explodes.

If you want to make the best of your gas, you will use the lowest possible octane before your car starts to ping. Things that can make you ping? Carbon deposits on your pistons causing the compression ratio to be too high for 87, high cylinder temperatures from failing cooling system or turbochargers.

If your car is made for 87 and you put in 91, you are effectively wasting a portion of the gas. For example, if you burn 98% of 87 octane but only 90% of 91 octane, you are reducing your possible gas mileage. You want to burn AS MUCH of the fuel as possible during the combustion cycle, so running a high octane gas in a low-octane requirement car is a WASTE.

The car I'm driving is 11.25:1 compression ratio. A stock Cougar, IIRC, is 10:1. You figure it out.
 

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PREACH IT BROTHER!

Higher octane ostensibly retards timing to resist combustion.

To increase performance, many people artificially ADVANCE timing, with adjustable cam gears, etc.

The two seem to be at odds, don't they?

One of our Ohio NECO members couldn't get out of the 16's on the drag strip, and it's because he was using high-octane gas in his car. The next time at the strip was after a few tanks of regular, and he lost 4 tenths off his time.

Screw you guys and yout "91 is the good stuff". Unless you have high compression or forced induction, you might as well be giving ME that extra $3 per tank, for all the good it's doing you. I'll send you my PayPal address, PM me...
 

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:rofl: No no, send it to me, since I actually DO need Premium :rofl:
 

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I just put a tank fo 93 in, why you ask? Dyno tuning tommorow woot! Getting a real chip not some off the shelf crap. And I will benefit from the 93. Before this I used only 87.
 

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My wife filled up with regular on Friday morning, and so far we've gone farther on the same amount of gas than when we were using premium. I realize it's probably too early to tell for sure (<100 miles), but so far, it's looking good.

Originally posted by: NorCalCoug
If your car is made for 87 and you put in 91, you are effectively wasting a portion of the gas. For example, if you burn 98% of 87 octane but only 90% of 91 octane, you are reducing your possible gas mileage. You want to burn AS MUCH of the fuel as possible during the combustion cycle, so running a high octane gas in a low-octane requirement car is a WASTE.
Does the reverse hold true? If your car is made for 91, and you were burning 98% of 91, could your efficiency increase to closer to 100% by putting in 87, thus improving your mileage?
 
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