What oil?

[mangocrazy]

I've trawled through as much of the forum as I can, but can't find any discussions/recommendations for type and grade of oil to be used. This in itself is pretty amazing, because most motor-related forums have countless 'oil threads'...

I'm fairly sure that the manufacturers recommendation 'back in the day' was for 20w-50, but oil technology has changed so much in the last 30 odd years, and the choices nowadays are so wide that I'm a little confused as to what I should be using. The car is a 1980 Spider (series 2 facelift model) with the 1995cc engine. The engine is entirely standard and has done approx 60k miles. The only slight proviso is that the car only gets used in the summer time in the South of France (lucky old car), so it won't have to deal with running in winter temperatures, but will have to deal with long periods of inactivity and potentially high temperatures (low to mid 30s C are quite normal, occasionally low 40s C).

Also, does one go with mineral, sem-synthetic or fully synthetic? I can't really see the point in full synth, and am leaning towards semi-synth 20w-50. Any recommendations/suggestions?

[HFStuart]

The handbook gives you plenty of choice.

10W30
10W50
15W40
15W50
20W50

I'd be inclined to leave the 30 grade alone and go for something a bit thicker the 15W40 probably but I shouldn't think it's going to matter too much so long as it stays in the sump and doesn't leak all over your drive !

I'd agree that fully synth isn't worth it, you're not going to be doing mega miles after all.

[rossocorsa]

the typical recommendation at the time the cars were new was for 10w40 ( if I remember right), that was certainly the case for Fulvias and 2000 I'd go for a 10w40 semi synth myself assuming that engine wear is minimal other wise something a bit thicker at the hot end

[75coupe]

I use Penrite 25w70 here in Queensland Australia, where it is normally between 30 and 40 degrees C in summer. (and occasionally hotter....) However I do Hillclimbs/sprints and find lesser grades suffer oil pressure loss when hot, even with the oil temp gauge reading in the middle, although the engine is a little tired now.

[WestonE]

As an ex oil company type I get over excited on this topic. I personally use 10w60 Selenia in my highly tuned Montecarlo with great power and reving to 8500 rpm. This is not for all Beta owners, however hot or cold climate you want oil to the bearings asap in start and warm up so go for a 10w xx or even 5w xx if you can find it. At the top end hot conditions dictate you should be looking for at least a 50 grade and the tolerances in Beta engines mean this makes sense. So on balance a 2 step approach:

Use a 10w 40 semi synthetic name brand oil for 500 miles as a cleaning agent and then change to a 10w -60. There are a number of options from Valvoline, Castrol, Fiat Lubricanti (FL).

Used with a high quality filter that has anti drain down you get a clean running engine with great protection from enjoyment!

I hear a lot of folk law about synthetic oil being "too thin" "P ing out everywhere" etc. Well made engine oils contain detergents, dispersants, anti-corrosion and anti-wear agents that cling to the metal. This means they will clean the engine from the inside removing carbon, varnish and sludge holding it in the body of the oil so that it leaves when you drain the oil. Consequently if your gaskets and seals are shot you might get more oil leaking giving you a big clue to replace them before you get local damage to the end of the cams or crankshaft. BUT there will be better lubrication to vital bearing drillings and things like piston rings and cams.   

You may well get better compression and less friction and hence more power.

I have avoided a technical deep dive , but i hope this helps

Eric

[thecolonel]

Thanks Eric,

that is very useful information.

Geoff