When I was a kid my Dad would go to the petrol station where the choice was diesel or a selection of leaded petrol ranging from 2 star to 5 star.

At some point unleaded came along and the leaded stuff was phased out. After this if you had a car that was registered pre 1980-something you had to put an additive in your tank along with your unleaded petrol.

A few months ago I bought my Buggy which is pre 1980-anything and one of the things I asked the seller about was if any additive was required for the fuel and he said no.

Could someone please tell me whether I have been misinformed or why it is that an additive is no longer required. Has the fuel changed since the 80's?

I have not had any problems and have not driven the Buggy much due to lockdowns and crappy weather but if I should be putting an additive in the tank I will do so. I don't want any unnecessary engine issues.

VW engines have always been fine to run on unleaded, officially since 1967 but in reality since day one as they've always had hardened valve seats in their alloy heads.

A lot of VW parts places used to sell unleaded conversion kits: heads, cylinders & pistons and an 009 distributor, these firms were crooks and haven't had a penny of my hard earned cash since.

VW were very ahead of the times when they designed their air-cooled engines.

All the valves and guides are already hardened so will quite happily run on unleaded fuel without issue.

Many people have been fooled into installed newer unleaded heads on a VW engine, when they were already compatible.


That being said.  The issue now is not the unleaded fuel, but the bio-ethanol being added to modern unleaded.  This is not a problem for the heads, but rubber components do not like it so make sure the fuel lines are upgraded to ones that can handle this. 

There is also the potential that the ethanol could also play havoc with the internals of the carbs.  Finally there appears to be an issue with how the fuel can absorb water and how this can separate in the tank over the winter layup.

The best way round this is the use "Super Unleaded" 98 or 99 RON.  This either doesn't contain or has a lower value of the ethanol.

That is all really good to know. Thanks very much.

Quote from: Roadrunner on February 10, 2021, 11:42:07 AMThe best way round this is the use "Super Unleaded" 98 or 99 RON.  This either doesn't contain or has a lower value of the ethanol.

So my 50/50 mix of chip fat and red diesel is no good?

Quote from: Manxdavid on February 10, 2021, 12:25:53 PM

Quote from: Roadrunner on February 10, 2021, 11:42:07 AMThe best way round this is the use "Super Unleaded" 98 or 99 RON.  This either doesn't contain or has a lower value of the ethanol.

So my 50/50 mix of chip fat and red diesel is no good?

It's fine so long as there's no booze in there as that's ethanol

Most of my booze is methanol based. may be why I'm blind.

Quote from: Flags on February 10, 2021, 10:03:53 PM
Most of my booze is methanol based. may be why I'm blind.

Could explain why old blokes pipes get leaky too!

Speak for yourself