Fuel grade in A6 4.2

Cody Forbes cody at 5000tq.com
Wed Apr 14 10:20:11 PDT 2010


Retarding the ignition timing is not a "free" fix for the problems  
caused by running octane below the factory recomendations.

With the timing retarded the fuel doesn't have as much time to burn  
before the exhaust valve opens. This means higher EGTs, higher under  
hood temps (faster deterioration of rubber and plastic), and worse  
emmissions.

With the current fuel prices in my area the fuel cost savings of AN  
ENTIRE TANK FROM BONE DRY (21.5 gallons) on the A6 4.2 would be  
roughly $2.10. For two dollars it seems just not worth using lower  
octane. You can save more money by switching to Geico...

-Cody (mobile)

On Apr 14, 2010, at 12:53 PM, SteveR <srosen at starxray.com> wrote:

> I usually don't comment on comments or opinions. Everyone has one. But
> in this case I'll add mine only because the answer was a little
> condesending. The original question said nothing about oil type usage
> either.
>
> A lower octane gas is not a lower quality gas. Gas may differ company
> to company however. It's what the engine is designed for to optimize
> performance. If the timing is retarded for lower octane no problem as
> long as you don't need the power.
>
> I often use 87 in my passat 2.0 if it's used on a long trip at very
> constant speeds. Also around town. No problem at all.
>
> I will add that overall if you use lower octane but push the car your
> better off using the higher octane. The gas mileage will be better.
>
> My opinion only. All else chime in.
>
>
>> Eric,
>> If your friend cannot afford the car, you as a trusted and good  
>> friend
>> should advise him to sell it before he destroys it. "Saving" money
>> on low
>> quality gas and oil costs far more money sooner than you think. He
>> should be
>> using Top Tier rated gas www.toptiergas.com and synthetic motor oil  
>> to
>> prevent spending much more for repairs sooner than later.
>> Best,
>> Tim Leonard
>> ESCARGO
>> Michigan
>>
>> -----Original Message-----
>> From: quattro-bounces at audifans.com [mailto:quattro-
>> bounces at audifans.com] On
>> Behalf Of Eric Sanborn
>> Sent: Wednesday, April 14, 2010 7:34 AM
>> To: Quattro List
>> Subject: Fuel grade in A6 4.2
>>
>> A friend and coworker of mine just got an A6 with the 4.2 engine. It
>> is a
>> 2000 model year. It calls for 91 octane. If he is willing to be a
>> little
>> down on power can he use 89 mid grade? I seem to recall that it will
>> just
>> retard timing. Is this correct?
>>
>> Thanks
>> Eric
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