can I use synthetic oil in a 1979 Lotus?

[TimHaydnJones]

I've recently re-commissioned my 1979 Eclat after too long in the garage.

I've always used mineral oil, is that the only oil I should be using or can I consider the modern semi or fully synthetic oils?
And if I do need to use gool old fashioned mineral oil, is Halfords 20/50 OK or is there a better alternative? I used to use GTX when the car was regularly used yonks ago

[POORCARDEALER]

You may find it leaks like a seive due to the "thinness" of fully synthetic....I would stick to castrol gtx or the like

[marshalla]

Regular debate on this at lotusexcel.net. Our conclusion is that the oil thickness is more important as the 9xx series engines were designed with greater tolerances than modern engines. Anything much below a 10W50 or 10W60 is false economy as more will burn off. Synthetics are ok as they do produce a bit less wear - but it depends on your driving style.

[Sam_68]

You can, of course, get Mobil 1 synthetic (for example) in the correct weight.

[Justin S]

dont waste money on mobil one, valvoline racing 20-50 is fantastic stuff and under £20

[Oilchange]

use the right viscosity and it will be fine I'm sure. Works for my Esprit anyway. Used Mobil 1 before,now use Fuchs/Silkolene Pro R Ester.
£35.565 / 5 litres if you buy 2. and its... er, RED!

[Peter Punter]

The usuall crap about synthetic oils being thin. The SAE applies to all types of oil.

A 20W50 synthetic oil has the same viscosity as a 20W50 mineral oil, plus a number of advantages.

Marshalla is correct about using an oil with suitable viscosity.

I use Bardahl in my cars because it contains Polar Plus which reduces friction by 90% and they have an extraordinary stability and resistance to thermal oxidation. All my Lotus cars, (Elan+2, Europa, Elise S1 (x2 race cars), Elise Sports Racer) run on Bardahl Competition oils which contain Fullerene C60 which reduces wear by 70%, gives more power and torque, and protects the engine should I experience coolant shortage.

Justin S: Please can you enlighten me as to why valvoline racing 20-50 is fantastic stuff. Thanks.

Edited by Peter Punter on Saturday 13th November 20:28

Edited by Peter Punter on Saturday 13th November 20:29

[POORCARDEALER]

[quote=Peter Punter]The usuall crap about synthetic oils being thin. The SAE applies to all types of oil.




If I put fully stnthetic oil in my old 964 c2 it leaked badly.....if I put semi in it hardly leaked at all.


Why would that be then?

[Oilchange]

because you had a leak?

[POORCARDEALER]

Oilchange said:

because you had a leak?

Side splitting.