[Hoya Lawya]

This is my third tank of gas. The first two had been premium. I followed the sales rep recommendation on using midgrade fuel this time. The guy, owns a 1.8T Jetta, said that he had read something about engine problems with 93 fuel and told me that the 89 gas would make no difference and save me money.
Well, now I am feeling that the engine noise is louder and the performance considerably drops - I kind of expected the drop in performance but not the noise. My Passat now has 970 miles on it. Is this normal?




[Modified by Hoya Lawya, 2:45 AM 2-14-2002]

 

[dizgusted1]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (Hoya Lawya)

after 54 months of using only premium grade in my 1.8T 1999 passat,I now use regular.this was after reading a car column in the newspaper written by a famous car reviewer whose name I dont recall.he said he has run his 1998 1.8t since day one on regular,had no problems.he said the car automatically has adjustment for octane.I think he's right.my cousin has the same car and he has always used regular too.no problems.

 

[idale]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (dizgusted1)

The engine will compensate for the lower octane by retarding timing whenever it detects knocks (and slowly advances it until it knocks again, when it'll begin the process all over). So there might just be problems later on in the engine's life by using regular instead of premium all the time, in addition to losing performance and potentially losing gas mileage.
Myself, I figure the few extra cents per gallon is worth it in keeping my engine running at peak efficiency and preventing knock (as opposed to making the engine compensate when it happens). http://****************.com/smile/emthup.gif

 

[DCdave]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (idale)

quote:[HR][/HR]So there might just be problems later on in the engine's life by using regular instead of premium all the time, in addition to losing performance and potentially losing gas mileage.[HR][/HR]​

One of those problems is purported to be carbon build-up. This sounds reasonable to me, but there is debate about exactly what will happen when regular fuel is used instead of premium on a long term basis.
Hoya Lawya, someone else here or at ClubB5 was told by their service tech to use mid-grade or regular fuel too (is the Search function operating right now?). It was sometime ago, but I remember that some people suggested the car owner should get that advice in writing in case a problem possibly came came up in the future and led to a dispute over warranty coverage.


[Modified by DCdave, 2:36 PM 2-13-2002]

 

[av_audi]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (Hoya Lawya)

Let's see, you are ignoring the recommendation of those who design and build these engines in favor of the "opinions" of some "sales guy" and a "famous car reviewer"???

Sure, the knock sensor will retard the timing to compensate for the lower octane, but that also means reduced power and mileage.

 

[Altair 4]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (Hoya Lawya)

I recall reading the same post mentioned by DCDave, either here or on Clubb5. If it were my dealer telling me this, I would demand to see the TSB that shows that it's sanctioned by the manufacturer. No TSB, then nothing but premium. It's that simple. I can almost see the future forum notes:
"Four years ago, some wanker at the dealer told me to use regular or midgrade, and now my engine is kaput. The wanker no longer works at the dealer and VW won't honor my warranty. What should I do?"
You bought a $25,000 car. The difference over a year between premium and regular is maybe $60. If you can't aford the $60, maybe you should have bought a cheaper car.
Why does this keep resurrecting?

I don't even own the car yet, and I'm gettin' all bothered by this topic!

 

[D-n-TYKE]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (av_audi)

I agree with av_audi, do you think that VW is in bed with the oil dealers or something. They gain nothing (maybe even lose some buyers) by recommending premium fuel. Yes the motor with compensate for the lower octane but for the lose of power and possible problems down the line I'll pay the extra $1 or $2 a tank. If octane didn't matter why do all the racing teams run upwards of 106 octane??????


[Modified by D-n-TYKE, 12:37 PM 2-13-2002]

 

[av_audi]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (D-n-TYKE)

quote:[HR][/HR] do you think that VW is in bed with the oil dealers or something.[HR][/HR]​

Actually, my manual clearly states how not all fuels brands "are the same" or "created equal", I can't remember exactly. I think the reference was to the detergent effectiveness of different fuel brands. No names were mentioned though (of course). I'll check for the exact wording.

 

[Triumph]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (av_audi)

Stick with premium. You Will lose power with the lower octane gas. Like someone else said, who are you going to believe: the guys who DESIGNED the car, or 1 or 2 rumours here and there?

 

[oceanengineer]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (av_audi)

I think I've noticed a difference with different brands of 93 octane fuel. After the last fill-up my mpg dropped a bit and I felt the engine to be less responsive. I filled up again with a different (more expensive brand) and the mpg is back where it was and seems to be running smoother. Of course it could just be psychological - trying to justify the extra expense! - but I notice the difference. I wouldn't use 89 octane fuel w/o a really good reason (and a couple of bucks a week is not one of them).

 

[Hoya Lawya]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (Triumph)

quote:[HR][/HR]Like someone else said, who are you going to believe: the guys who DESIGNED the car, or 1 or 2 rumours here and there?[HR][/HR]​

Well ... my 2002 manual, under the technical data section, says that both Premium (91-97 AKI) and Regular (87-90 AKI) can be used in a 2002 1.8T, but Premium gasoline is recommended for maximum performance. The words of my sales rep was note the sole reason I pumped 89 into the tank yesterday. Out of curiosity, does the manual in a 2001.5 say the same thing? Nevertheless, my car will never taste anything less than 91 in again. I will drive to WV this Saturday just to burn the gas.
Regards

 

[The Swami]

Re: Engine noise is lowder when using 89 octane grade gas in 1.8T - Normal? (Hoya Lawya)

Whoa, the debate about using high octane gas still continues. Honestly today's gasoline has alot of detergents in it which somewhat prevents carbon-buildup. I also agree with AV_Audi, stick to what the manual recommends because that same salesperson is not going to be there when your oxygen sensor or fuel filter goes bad!
Here's a tip: After your 2nd Oilchange, go to your local auto-repair shop and buy a can of B&G's 44K and add it to your gas. This will keep those injectors and fuel filters clean, so your baby will run smooth.