The Stovebolt Site Forums The Shop Area Engine Shop Castrol 25W-60

Found 10 jugs of Castrol 25W-60 High-mileage motor oil at a thrift store for $10 each. Will it work in my 235 with a bunch of miles on it, or is it just too heavy? I live in San Antonio, TX where we play golf on New Years Day……. Sometimes in shorts!

$2.50 a quart is a deal! I hope you bought all 10!

I'd buy it at that price, just to use as cutting lube for my drill press!
Jerry

I bought 4 gallons because it was so cheap, but still don’t know if it would harm the 235. It’s plenty hot in the summertime here, and usually not too cold in the winter. I wouldn’t drive the truck on blustery days anyways.

I doubt if it would harm the 235. There would be a little drag on performance, as it's thicker than the recommended 30 wt oil. A little additional wear on the oil pump/distributor drive gears maybe.

What would that have been for originally? I have never seen what appears to be engine oil that thick.

Harley Davidson recommends 20w-50 oil and possibly 60 wt if ambient temps are above 80F, according to their website FAQ page.

The oil manufacturers tout high viscosity oil for use in high mileage engines, but all that does is delay the inevitable rebuild.

I’ve been using 20w-50 in my Blazer for the last 300,000 miles and it now has 437,000 on it and still going strong.
That is also in the Seattle area, not known for very hot weather.
I would not be afraid to use it in your area.

Is there a date code on it? I ask because according to The Motoroil Geek the addiditve package separates out after about 2 years of sitting and can't be reintegrated.

The oil doesn't actually get thicker- - - -it stays at the 25 weight viscosity all the time- - - -it just lubricates like a 60 weight when it gets hot. Worrying about engine damage from "thick" oil is a big waste of emotional energy. Run the stuff and be happy with it- - - -the engine won't care!
Jerry

We used to sell 25W60 to guys with inboard boat motors. And some aircraft engines use it. I don't stock it any more.

What is the shelf life of oil?

Most say 4 or 5 years if unopened and stored in a cool dry place.

If in doubt, pour it into a jar and see if there is sediment in the bottom or if it feels gritty. That will be the additives settling out / going bad.

Thanks everyone for your comments about the oil. I’ll take Jerry, Kevin, and Pre ‘68 Dave’s advice and use it in my Texas 235. Lord knows it gets hot enough down here to thin it out 9 months out of the year!

So you not recommend using on 216 engines?

I didn't see anyone mentioning not using it in a 216. It could be used in ANY engine.

Run it.

On a 100 degree day, and a worn engine sure. All the big old piston airliners used SAE 60 equivalent oil. I dumped gallons and gallons of it in DC-3's as a youngin they were Pratt & Whitney R-1830's. Oh yeah it stayed in there for the winter time as well.

Shelf life of oil ? Hmmm thousands of years in the ground? Additives ? maybe warm it and shake it up?

Wow. 25W-60 could be rear end gear lube in deep winter in Montana. (kiddn'...almost)

I know you're kidding Wally but for educational purposes, I should point out that the viscosity ratings for motor oil and gear oil are completely different.

Gear oils are a lot thinner than you might expect from their viscosity numbers. 75w-90 gear oil is actually the same viscosity as 10w-40 motor oil.

I was skeptical about what Otto said, but it's true. Motor oil and gear oil use different scales. Here's a chart for comparison.

Not only is the viscosity different but lubricant for the rear must have EP (Extreme Pressure) additives and these additives will attack the synchronizers in in a transmission. Engine oil can be used in a transmission. Especially spur type transmissions. Many people find synthetic oil in transmissions objectionable because it reduces the effort of the synchronizers.