Re: Which gas should I use?

[Orin Eman <orin@WOLFENET.com>]

> The owner's manual for my 5KT says I should use 92 octane gas. I
> understand that this is US AKI octane number, so it is calculated using
> (research+motor)/2 formula. The gas pumps here in Europe are labeled by
> research octane number. I was using 95 octane gas until someone on this
> list (Alex, as far as I remember) posted the conversion charts for
> research and motor octane numbers and I realised 95 RON is equivalent to
> only 90 AKI, so it seems that I was using wrong gas. I started to use 98
> octane gas, the problem is, it's not widely available here in Poland and
> the only gas stations that always have it are those belonging to the
> Finnish oil corporation Neste. They import 98 octane gas directly from
> Finland and they advertize it as "the first reformulated gasoline in
> Europe". I know that reformulated fuels are being already used for many
> years in USA and I heard very bad things about them on this list. I
> didn't notice any improvement in performance or gas mileage using 98
> octane fuel, but I think the fuel pump is a little bit quieter (maybe
> this stuff has better lubricating capabilities?). So, what in your
> opinion should I do?
> 1) Use reformulated, "super clean, increases power, prolong catalytic
> converter life" etc. etc. 98 octane gas
> 2) Trust my knock sensor and use good old 95 octane gas (which is much
> cheaper, BTW)
> 3) Find a gas station that sells non-reformulated 98 octane gas? (may be
> difficult, though)

If it is a US spec car, it will run on US 87 octane.  It has two
ignition maps, one for premium (92) and one for regular (87) and the
knock sensor will cause the switch from the premium map if it
gets to maximum retard due to knock.  You should get slightly
better performance from the higher octane, but if there is any
alcohol in that 'reformulation', then that tends to reduce
gas mileage, so it may be a wash.

There is a fourth alternative - go half and half - half a tank of
98 then half a tank of 95 and see what happens.

Orin.