Expert: Harold Garabedian - 3/11/2008

Question
I have a 1968 Triumph Spitfire and have been told that it needs leaded gas only. How do we get this car to be able to drive it.It is in excellent condition and we want to give it to our granddaughter.We had to take the gas tank off and have it cleaned and lined.We have purchased new gas lines and need to have the carbs cleaned.I have a triumph catalog that has a fuel additive you can buy but I don't know if this will have to be added evrytime gas is added.Hope you can help us out.

Answer
There is a lot of miss-information out there on the matter of using unleaded gasoline in an engine built back in the day of leaded fuel.

Generally the discussion has a focus on the fact that engine valves, valve seats and other engine components intended for operation on leaded fuel weren't made from metals that are not as hard as the matals of today's engines. And the discussion continues that those older engines relied upon the 'lead' in the fuel to 'coat' the valves and seats to 'cushion' their contact.

While there is some 'truth' this, the impact of operating an older engine on unleaded fuel is over stated. An engine intended to operate on leaded fuel can be operated on unleaded fuel. Where concern is appropriate is if that engine would be operated at sustained high capacity, or sustained high power demand.

For technical and objective review of this matter see:

http://yosemite.epa.gov/ee/epa/eermfile.nsf/vwAN/EE-0034-1.pdf/$file/EE-0034-1.p...

http://www.unep.org/pcfv/pdf/VSR-FinalDraft.pdf

a more general publication on this topic is:

http://www.unep.org/pcfv/PDF/Pub-AECLP-Myths.pdf