Beware of Shell 98!

[LukeC]

For those of you out there still driving real Alfas with Nord engines: This trap is catching a few people out here and there...

If you are using the stock type rubber carburetor isolators: DO NOT UNDER ANY CIRCUMSTANCES USE SHELL 98!

There is something in Shell's 98 jungle juice that will turn your carb rubbers to jelly within a couple of tanks. I have been caught on a few engine builds I have done over the last few years until things clicked to me. This fuel will turn your carb mounts to jelly in short order (like a couple of tanks). When I first struck this, I though it was poor quality non-OE carb mounts, but it happened even with OE Pirelli ones. Common theme was ALWAYS the vehicle's owner was using exclusively Shell 98.

You have been warned! Like a ~$600 repair bill.

Just a quick word about 98 octane fuels in general: Unless you have a high compression ratio, you are wasting money on these fuels. A 2.0 Nord has a compression ratio of 9:1 and was originally tuned for 92 octane fuel. The actual calorific value of all petrol fuels is around 46 MJ/kg, the gains in power can only be realised when your engine has a higher compression ratio and you need the knock resistance. E.G: My Subaru has a compression ratio of 11:1 and requires 98 to run correctly. I am not going to get into why here.

What do I recommend? Anything but shell... In fact, don't even drive into a Shell service station in any of your cars. I use BP... for the purely scientific reason that it an ingrained habit.