Shell 20W-50 vs. GTX

Switch to a full synthetic!

Mobil1 makes a 15/50; Redline a 20/50 and Amsoil two 20/50s.

Get far superior portection and free up some HP...





Did you know Shell makes Formula Shell, Pennsoil, Quaker State, Rotella and Jiffy Lubes oil?
Shell in the US - Motor oils




Chuck

Generally, the "synthetic oil leaks" objection is a semi-myth. If the engine is old and cruddy inside and the crud is essentially acting as oil seals, then when the inherently more detergent synthetic is introduced, the crud is eventually cleaned out and leaks are revealed. It isn't the oil, it's just the seals and gaskets.

Synthetics also have a greater affinity for metal, ie, they cling better, so any leak looks worse because it spreads out.

I've been using Mobil1, Amsoil or Redline in Fiats and Alfas -and MBs and BMWs -for years, no issues. It's more expensive, but not much, and still a relatively small part of the cost of upkeep on the cars.

Just don't do what a friend's kid did who ran his Alfa OUT of ANY oil - SCREECH! - then asked his dad if he couldn't just add some oil NOW and it'd be ok?

Have a great day!

Chuck

lowmileage,

You strike me as fairly "old school" in your view of motor oils. I am, too. I think the Formula Shell 20W-50 would do just as well in your GTV as the Castrol. If you were racing, running a turbocharger or going for extended mileage between oil changes then synthetics might make sense.

Conventional motor oils have improved markedly over the last few years so that the quality gap between them and synthetics has closed significantly. But not the price gap.

Maybe you should be asking yourself a different question: Do I need a 20W-50 oil? If your engine is quite worn, the oil pressure tends to be lower than you wish, and/or your Spica or carbs are leaking fuel into the sump, then maybe you do. Your owner's manual probably specifies a 10W-50 oil. So that's what you (or a PO) should have used 30 years ago. Alfa specified that oil knowing it would shear down to a 40 or even a 30 weight with use and a some fuel in the oil. But that was then.

If your engine is in pretty good condition, you might find you can run a lower viscosity motor oil without harming your engine. In fact, considering that most engine wear occurs while your oil is coming up to operating temperature, using a lower viscosity oil that comes up to temperature more quickly than a heavier oil does can lessen wear.

A personal example: I have a 71 GTV with Spica. The PO had 10W-30 in the car when I bought it. I had the oil analyzed and found it was acceptable from the standpoint of wear metals and it had no measurable fuel contamination in the oil. However, I was not happy with the oil pressure once the engine was warmed up. I replaced the oil with Chevron Delo 15W-40, a robust conventional heavy duty oil. No problem with the oil pressure now, although the oil takes 10 or 15 miles of driving to get up to operating temperature. I have bought a case of Formula Shell 10W-40 to try out next change. It should provide good oil pressure if it stays in grade and it should warm up more quickly than the 15W-40. We shall see. The point is that you should experiment to find out what's best for your individual car.