Which Oil?

[Supermike]

Okay, so I was just reading over this thread with regard to today's oils and the missing additives, and was wondering which oil would be the best to use in my '67 352? Rotella T? A "High Mileage" or "Extended Performance" oil (such as Mobil 1 High Mileage 10W-30)? Something like Valvoline VR1?

It appears the Rotella T is a diesel oil, but can be used for gas engines, too. Mine - as far as I know - is a standard built 352, thought it *might* have a 390 cam in it (I haven't measured). It was rebuilt about 10 years ago.

Around here (Southern IN, Northern KY) the temps can range pretty drastically from one day or week to the next. For example, right now we get lows in the 70s at night and highs in the mid-90s during the day. But in about 3-4 weeks, that'll change to highs around 90 and lows in the 60s. Give it another 6 weeks after that, and we'll be looking at highs in the 70s and lows in the 50s.

My owners manual says to use 5/30. Many places around here use 10/30. To me, a multi-viscosity oil seems to make more sense than a single grade oil (SAE 50), given the temperature fluctuations around here. Because of the age of the engine, I don't think a synthetic is a good choice. It would probably find places to leak everywhere. But is finding an oil with Zinc, etc., THAT important after 10 years of running who-knows-what?

Input/advice is appreciated! I will eventually have this engine gone through, but for now I need it to hold up as long as possible.

[3406kris]

I think just doing regular oil changes and filter changes is a lot more important than the actual oil brand or weight. I've never heard of an engine failing because it had 10-30 in it rather than 15-40.

That being said, I use Shell Rotella 15-40 in all the FE cars I build. The crankcase of a diesel in a nasty place, and the oil for them is formulated to deal with it by adding anti corrosion and anti oxidation additives to the oil. Carbureted engines aren't able to meter fuel as well as an EFI engine, so they always wind up putting carbon and unburned fuel in the oil. Diesel compatible oils are made for this.

Well, thats my theory anyways!

[rubiranch]

I use Valvoline 10w30 Racing oil, the one that says not legal for street use on the can. It still contains Zinc and most of the other heavy metals that have been removed from newer oils.

[Supermike]

Thanks for the feedback... I do agree that regular oil & filter changes are more important than the brand. However, I think the value of weight certainly would come into play if you were using a 15-40 and it was 0° outside... right?

I was considering using either 5W-40 or 15W-40 Rotella T ... but wasn't sure which one, or if the Rotella was really necessary or "worth it". By logic, if I understand weights correctly, the 5W would be better to use in winter (it regularly gets into the single digits and teens around here), and the 15W would be better during the rest of the year. But to me, the 5-40 seems to have kind of a wide spread.

For reference, a gallon of 15-40 Rotella T at Autozone is $10.99, wheras a gallon of 5-40 is $17.99! Using @ 6 quarts of 5-40 would be one expensive change!

[rubiranch]

I ran Valvoline 20w50 Racing in my 79 F-250 with a 400 for 200,000 miles and it gets cold here in Utah and never had a problem.

[Supermike]

Thanks.... I could probably get by with the 15-40 year 'round here, as it usually only gets in the 0-15° range for a week or two, and my truck is now kept in the garage.

I just realized the Rotella 5-40 is actually a synthetic, which many say would leak more fluidly than classic dino oil. The price on the 15-40 is better, but I've also become aware of Rotella 10-30 or 10-40 floating around, as well. Will likely use one of those, but am still interested in everyone's opinion.

Thanks!

Mike

[Supermike]

Just found where there was some more discussion of a similar topic, for those interested:
http://www.fordification.com/forum/view ... quarts+oil