Unleaded
The question of whether it is OK to use leaded or unleaded fuel arose again recently and I realised there was no advice on the website. When I visited the factory earlier this year they gave me 255 pages of technical updates for the GTA (the last copy!) for the club library. The very last page addresses the use of unleaded fuel. As this information comes from the factory that built the cars we have to assume that it is correct.
OFFICIAL
| Vehicle | Super Leaded | Super Unleaded |
| R5 Turbo Type 8220 | YES | NO |
| A310 All Types 2700 VA | YES | NO |
| GTA D500 (Atmospheric) | YES | NO |
| GTA D501 (Turbo) | YES (not Swiss) | YES |
| GTA D502 (Turbo CAT) | NO | YES |
Regardless of what you may read or be told elsewhere this is the ONLY official information released by the factory. No explanation is given as to the reason for the unsuitability of unleaded fuel for particular models. There is no clarification whether this is a valve seat, timing or other issue.
UNOFFICIAL
I run my all Atmos and Turbos on unleaded without any problems. They will also run on LRP.
All GTA's with the late 'A' logo fuel filler can run OK on unleaded. All turbos are also OK.
The grey area is the early Atmos with the flat fuel filler cap. The official factory bulletin states they are unsuitable for unleaded but they have the same valve inserts as the other engines and no-one to date has reported a problem. If you are really concerned I would suggest adding an aftermarket additive.
As long as you buy a high quality/high octane fuel you should be fine.
97 RON BP Ultimate
98 RON Shell Optimax
99 RON Tesco Super
Yes... Tesco really do sell the highest octane fuel in the UK!
A610 & Le-Mans fitted with a catalytic convertor must be run on unleaded fuel otherwise you will destroy the CAT.