What engine oil do you use?

[KandJinmaine]

It's time to do an oil change on the Fiat. I have for years followed the advice of our long time Fiat guru from Redwood City, Ca. And used straight w30, preferably Castrol. There have been a few advances in motor oil since then....
I know this may open a can of worms, but what do you use? Ours is a 1980 FI, if that matters.
Thanks ,
Jefff

[klweimer]

I use whatever dinosaur based name brand 10W-30 is on sale at auto zone and then add a zinc additive. Apparently most modern oils don't have the zinc content they once did, and the flat tappet valve system on our Fiats really needs that. I use this, https://www.amazon.com/ZDDPPlus-Engine- ... words=Zddp , but I'm sure there are other good additives around. I don't use synthetics, as I don't think the cost is worth it and our engines were not designed for them.
Kirk

[aj81spider]

You should check your owner's manual. The manual for my current 74 and my old 81 were the same and they recommend 15W-40, which is what I have been using (with a zinc additive).

[stuartrubin]

Can someone explain what the zinc does? From my very naive understanding of the engine, the oil is just sputtering around lubricating and cooling the parts. Why zinc?

My mechanic (and old school Italian guy) recommended 10w40 for my '75 124, but never mentioned additives.

Thanks!

[kilrwail]

Here's an article that explains as well as any the benefit of zinc (and phosphorus) in older flat tappet engines - https://www.hemmings.com/blog/2012/10/1 ... r-engines/

I use Brad Penn (formerly Kendall GT) 20W50 in both my cars and have for years - it's over 1200 ppm of both.

[profcucchi]

I'm a convert to Shell Rotella Diesel 15w40

But I'm in Toronto, so there's a viscosity reason, too.

[vandor]

It's hot in Texas, so I use 20w50 Valvoline VR1 racing oil, which has zinc content. If the car has a catalytic converter then the oil should not have too much zinc, or the converter could fail.

[KandJinmaine]

Thanks for all the responses. I learned something today!!
Jeff

[KWL82]

Csaba, what is considered too much zinc? does vr1 have as much compared to rotella? ive been using rotella and havent had any issues but dont want to ruin my cat either.

[bulldog4444]

I use Mobile 1 0W30 synthetic with Lucas ZDDP (4 ounces, 1 ounce per quart) and a WIX oil filter. My engine has never been so quiet and run so smoothly.

[Odoyle]

One of the last Fiat gurus in Los Angeles recently told me we should be using either 30 weight oil or even 30w/50 in hot weather such as in Socal as anything with a lower viscosity will score the crankshaft and bearings apparently. I currently run Castrol HD 30W Conventional Motor Oil with a zinc/cam guard additive.

[RRoller123]

Using 4 qts of Rotella, then topping up with a little Mobil1. I run slightly over depth, but only slightly. It seems to like it.

NOTE:

If you rotate the dip stick 90 degrees, to allow for the Computronics installation behind the alternator (driver's side) you need to RECALIBRATE the mark on the stick. It won't read right. But it is easy to do so at an oil change. Just do oil and filter and add exact specified new oil amount, run the engine till warm, then let it set for an hour or so, pull the stick and make a mark across the new oil level location.

[vandor]

Csaba, what is considered too much zinc? does vr1 have as much compared to rotella? ive been using rotella and havent had any issues but dont want to ruin my cat either.

I do not know how much zinc is too much. Since neither of my two classics have cats I never looked into it. A mechanic friend told me to not use the VR1 oil in cars with cats. I suppose it also depends on how much oil the car is burning.