Re: 89 octane OK in 2.8L V6?

["Michael & Christine" <mlindner@netquest.com>]

And the voice of Andrew L. Duane's cat spake on high:

:No knocking, no loss of milage, no detectable problems at all.
:The manual in my car says 87 is OK, but the tank flap says 91
:(or is it the other way around?). I suspect it is a goof from
:translating european octane numbers to american ones.
:
Well, in my experiences (which I've already bored you all with) there is a loss
of mileage, but it may not be noticeable.  I mean, a 15 to 20 mile difference
per tankful is trivial, and driving conditions and habits will affect gas
mileage much more adversely.  But my point is this:  Those driving conditions
are a "constant" in the sense that they would be there regardless of fuel
choice.  And the slight difference in cost per tankful is made up in the slight
(hardly noticeable) increase in fuel economy.  But the real reason one should
use premium (IMHO) is that, like another posted, it burns cleaner, there are
less contaminants, and will keep your engine (particularly your valvetrain)
cleaner, longer.

Case in point:  My 1988 Jetta GLi 16v.  The only things to go out on it (besides
normal wear and tear) were the distributer and a faulty pre-pump.  Oh, and some
throttle switches, but whaddya want?  I've always used 92 octane and Castrol
Syntec.  This thing has well over 250,000 miles on it.  I've never had any motor
work done to it.  And I still routinely take it up over 100 mph.  It's a healthy
car.  Sure, it's not all due to using 92 octane, but that plays a part, I'm
sure.

So if the cost of premium is around 1/10 of a penny per mile more than 89 (see
my previous post for breakdown), and I've put 125,000 miles on it since I bought
it, I've spent about $125 more to run premium through the system.  BUT:  I
*haven't* had to pay for a $1000 head rebuild, or $300 for new injectors, or
$150 for a new main pump, or $400 for a fuel distributor, etc. etc.   So to me
the price of 92 octane is negligible.

I hate to use quotes, but Ben Franklin said it best:  "An ounce of prevention is
worth a pound of cure."

Best regards,

Michael Lindner
'88 5000cs Turbo Quattro (145,000)
'88 VW Jetta GLi 16v (250,000+)
'98 Chevrolet Suburban (7,200 and thankfully covered under warranty)