I do most of my own maintenance on my cars, and was wanting advice on oil type and weight for the V12 in my '88 XJ-SC. It was clean and full when I bought it in July, and I've only driven it about 250 miles since then, so I'll probably change it once a year in the spring like I do with my pickup that goes about 3,000 miles a year. I use synthetic 5w40 in my Mercedes E350, so if this is a suitable product, it would be nice to use what I keep around anyway. A store near me also carries Castrol Syntec full synthetic 5w50, which is a product I haven't seen much of anywhere else, if you think that might be preferable. Thanks!

Submitted by dhall@hallandh… on Wed, 10/24/2012 - 21:44

For anyone interested, just today in fact I got an email advertising a new Hemmings Motor News classic car oil, with the zinc and other additives for flat tappet and other classic car engine parts. As I recall there were three types, 10w30 and 20w50 synthetic blend, and a full synthetic, maybe 5w50. Anyway, the pricing was about $55 for a 6 quart case, so not too bad for that type product. I'm sure HMN is just licensing their name to someone's oil, but still, HMN is a trusted name and I don't think they would let their name go on crap. Might be of interest to some of you. AMSOIL and Royal Purple also have classic car oils if you're interested.

Submitted by dhall@hallandh… on Tue, 10/23/2012 - 23:30

FWIW I have looked at several oil manufacturer sites with application guides and they all recommend 5w40 or 10w40 in the V12. But, as has been pointed out, it's hard to go wrong with good 'ol 20w50, Castrol GTX is what I have used in older cars, especially in summer. I just hate to crank them on a nice winter day (40ish in my area) for a brief ride with such a relatively heavy oil. Shell Rotella Synthetic 5w40 is another possible good choice, a heavy duty oil that's available about anywhere.

Submitted by silver007@shaw.ca on Mon, 10/22/2012 - 22:44

I believe Quaker State or Penzoil being the best in conventional oils.... I have heard that the synthetics do not have as good additives for flat tappet engines..... the additives are necessary to combat the sweeping action of the cam lobes on the buckets which sit on top of the valve gear...... Many club members with this older style of engineered engines are using oil developed for diesel engines... So take your pick, I am running 10- 40 diesel oil in Silvers engine.

Submitted by dougdwyer1@com… on Sun, 10/21/2012 - 21:54

Most V12 owners use 20/50 weight unless use in sub-freezing conditions is likely.

As for brand and type, I'll leave others to comment. I'm a "Whatever name brand is on sale" type of guy :-)

Cheers
DD