Motor oil for a 84 fiat spider

[larrybarone]

I'm confused , what is the correct oil to use. Someone mentioned15w 40 but the auto parts store says it's for diesel vehicles.
I also saw 20w50 used on a you tube video.
Does the spider have a catalytic converter.
I bought the 20w50 but not sure I bought the right one.

[courtenay]

Lots of us, including me, use the oil for diesel vehicles because it has the necessary zinc additives that our engines need.
If you do a search on "oil" on the forum, you will get more information than you will ever need on what is hot and what is not for oil.

[So Cal Mark]

if you get an oil without zinc, use an additive. Otherwise the life of your camshafts may be shortened

[RRoller123]

Can you folks list a couple of the additives that you recommend? I am presently using Castrol 20W-50. Thanks. Pete.

[kmac33]

As stated, if you do a search, you can pull up a number of oil threads that will give you enough information/opinions to make your head spin! For our Spider's engine health, the most important factors are using an oil with healthy zinc levels, changing the oil on the correct schedule and keeping the correct oil level in the engine.
From all of the research I have done over the last couple of years, I found that Shell Rotella has the highest zinc levels.
Redline makes a good additive: http://www.summitracing.com/parts/RED-81403/
as does Edelbrock: http://www.summitracing.com/parts/EDL-1074/

[So Cal Mark]

I offer a product call Cam Shield. Besides Rotalla, Castrol GTX has zinc but at a lower level then the Shell oil. Most racing oils are going to have zinc, but they can get pricey

[RRoller123]

Thanks, Mark. That sums it up nicely.

[larrybarone]

Is there a catalytic converter on the 84 spider and will the high zinc content in the oil harm it

[So Cal Mark]

there is a cat on the 84 Spider and zinc will shorten its' life. Not using zinc will shorten the life of the camshafts, so pick which one you want to wear out