Motor Oil recomendations for winter

I've been using 20w50 oil since I got my 71 bgt in April. Should I go to a different grade for low temps in the Ky mountains when it may get to single digit temps?

The reason for a multigrade oil is to cover varying conditions. Stick with the 20-50 unless you get down below 20 degrees for an extende period, at which time you might want to go with 10-40 or 10-30.

Dito on what Chris said.

I agree with Chris and Tom.

Tom ,
I understand that the reasoning for using 20w50 in this engine is because the oil clearance in the main and rod bearings is a little larger than what you see in todays engines. Is this correct ?

Thanks
Steve

Not on main and rod clearances. even the most modern engines still adhear to the .001 to.0015 new. Lighter weight oils being used or recommended in new cars, because of complex valve train components. For example my two other cars are a Isuzu Trooper and a Acura 2.2 CL. The Trooper has four camshafts with hydraulic lifter/buckets, the cams are hollow for the oil to flow through and out each cam lobe. I started out using 20w50 but it caused too much valve train noise, went to 10w30 and it became quite as a mouse. the Acura's valve train gets ugly, the VTEC is a more radical third lobe ,jabbed between the each "normal" cam lobe that has a tappet follower that remains collapsed (it just flopps around on the cam not doing anything) until an oil servo opens oil flow through a galley that locks a pin in the lifter and forces it to ride the "radical" cam lobe and bypass the "normal" lobe. Mine is a single cam VTEC 12 valve(150hp 2.2 litre), but the Preludes use a twin cam 16 valve VTEC(195hp 2.2 litre)with same principle, but more valves and an extra cam. Both engines require multiple oil jets squirting oil all over this engineering marvel of flying valvetrain to keep it cool and lubricated. My point being is both the Trooper and the Acura have systems that flow mass quantities of oil over the valvetrain to lubricate and cool and don't want or need to have heavier oils hanging around up top to lubricate, like a conventional old school valvetrain like an MGB's. The new BMW M5 actually has oil pumps that scavenge oil out of the nooks and crannies of the head, to keep oil drag on the valvetrain to a minimum.

I haven't heard that. My thoughts on using 20/50 in 4 cyl engines is,because they work harder to do their job than the V8 engines. If you think back we used 10/30 in the old flat head Fords V8 engines. Then you take the V-Twin HD's I used straight 70 weight. Not too far from gear oil.

I agree, I am a 20w/50 fan, I do goto 10w40 in the winter in the GT, just because I like to not see my oil pressure gage dwindel at 0 psi for what seems like a lifetime(seems like a lifetime) before anything happens.
Read any new car owners manual and you'll see a statement like "we recommend 5w30 for improved fuel economy etc...." Goto the International Troopers owners group website and read all about heavy motor oils creating problems with valvetrain noise in Troopers because of lifter galley being to small for the heavy oil. The engineers designed the galleys for lighter oils.
AMSOIL makes 0w/? oil, must be a need for it. I think its all about fuel conservation.

I'll come down on the side of Chris and Tom B. here. 20w/50 for 'normal' temps, and drop to 10w/40 or even 5w/30 for prolonged periods much below freezing.
IF you really want to get technical, here's what MG recomends in the late 60's/early 70's shop manual:
All temps above 10F - 20w50
0-20F 10W30
below 0F 5w30

Now just for giggles, I'm going to try some 5w50 syn. blend on my next oil change to see how it works.
H.

I use half and half syn and regular 20/50 in all my cars. We did some reserch on the SCCA race track and found that we got less engine wear with this combo. I also talked to Castrol and they told me 50/50 mix is as good as straight syn. I sponsor 4 cars in SCCS racing and am there at the track to keep them from DNA.

Sounds interesting.Would you recommend using the 50/50 mix right after a rebuilt or would you allow for some break in time. If so ,what kind of milage?

Thanks in advance
Steve

Tom,
The stuff I bought is the Castrol 5w50 blend of synthetic and regular oil, not the straight synthetic. Have you tried this stuff? I thought I'd try it in my daily driver before I use it in a fresh rebuild I've got to install in a month or so.
H.

Two very good queations. Thanks for asking them. No, I DoNot use it in a brand new engine. I put straight 30W in at first. I personally put the first 100 miles on all my rebuilds. Re torque,ajust valves, change the oil to 20/50 castrol for the next 1000 miles. My customers bring the car back to me for check out,retorque and valve ajustment. I then put the 50/50 blend.
Harlan,I use Mobil one syn. and castrol regular. We found through other racers at the track and through our own test that Mobil one was the best syn. I do like Castrol oil and other than syn. it's all I use.
One other thing I still change my oil every 2500 miles.

Years ago I worked in a gas station. There was one guy who drove a 60 or 61 Ford Galaxie that was totally worn. The engine was one oozing oil leak, but it didn't smoke. The guy always had us put in a quart of DELO 30, which was way spendy compared to oils you could have bought for a whipper, so I asked him why. He told me his engine had never been touched, had 150k on it, all because he used this deisel engine oil (extra heavy on detergents). I've always wondered why everyone didn,t use DELO oil?
At the price of syn oil, have you played with filtering to recover your 2500 mile oil?

No ,and we have a co pick up our use oil who can do that. It's my feelings that as expensive as it is it is cheaper than going through one of these brit motors. I also use Mobil One oil filters which are $10 a pop. If you took a new mobil one oil filter and compaired the weight of it to a cheap oil filter you will be impressed at how much more it weighs.

About 25 or 30 years ago, my father bought about a 65 Dodge Monaco with a 318 in it. It had about 80,000 miles on it, over the next five or six years he put another 100,000 miles on it. In his usual manner, he changed the oil in it exactly three times, or on the average every 33,000 miles. Understandably his bottomend went. I told him he basically got what he deserved. When I pulled the engine down to see how much damage his neglect had caused, I was totallt shocked because all the bearings were in excellant shape and what had happened was the crank broke where there was a casting flaw inside it. I put a new crank and bearings in it, he continued to service it in his regular manner, aand drove it for another 60 or 70,000 miles. He then gave it to my younger brother who drove it for another 2 or 3 years. When he finally got rid of it had about 300,000 miles on it and it never had the heads off to my knowledge. I change my oil way more often than my dad, but I sometimes wonder if we overdo it a little bit.

Does it matter if you add a quart of 20/50 Castrol brand oil to a stock 4 banger that had Havoline brand 20/50 changed into it a couple months ago?

Gary,
With the price of motor oil,(compared to rebuilding an engine) isn't it cheap insurance to keep the oil changed at the recommended interval or sooner? That's how I've always seen it, anyway.

Sam,
Everything I've read or heard about oil says that as long as the oil meets the spec for the engine, go ahead & put it in. At the same time, the oil manufacturers recommend that you not mix brands "because of the different chemistry of the additives." Or, they want you to buy more of THEIR oil, rather than somebody else's. You decide.

Gary Lloyd, Sam C., Jerry P

I can not prove this, so take it with a grain of salt…
I had bought a '64 Dodge PowerWagon Panaled truck' in 1981.
I was told it had 463,000 and the engine had never been touched.

A county correctional facility used it as a prisoner mover, from the prison to the fields.
I did not believe him, but the old truck started right up with new (oil, gass, fuel, and plugs and point)
So to answer your question about the 318 and the 225 slant six, they both have something in common.

It is not the engine or standard transmission, that fall apart it is the vehicles..(by the way the PWTruck, had a 225slnt 6, if correct on the milage.
life ended at 570,000(not the engine, the truck).
69 Dodge Corannet, life ended at 3**,000

Now for the next grain of salt..
Lubrisol, a company off of HW225 in Dear Park. Makes (Penzsoil, Quaker State, Hovoline, O'Riely and many more). They are made the same except the additives that are added to the individual brand oils.
Castrol is not made there..

I agree, it is cheaper to change the oil regular. I'm just asking are we going a little overboard changing every 2500 miles?

Gary,
2500 to 3000 mile oil changes is probably a little overboard if 90% of you driving is on the freeway at speed. The problem is that for most of use, we spend 90% of our time on 10 to 15 minute drives where the engine never warms up properly, or stuck in traffic.
That kind of driveing ends up with water from condensation and contaminates from engine compustion building up in the oil, which eventally end up forming acids. The additives is the oil help counter act this formation ( along with foaming and a dozen other things..), but are eventually used up.
I'd rather change mine at or before 3000, and use a premium quality filter, than take a chance.
H.

If thats the kind of driving you do, it is kind of hard on your whole car, the transmission oil never warms up. Up here in Canada we have to drive 15 minutes to get to the end of our driveway. Then to catch the local dogsled we have to drive anothe hour.

Remember who set the oils change intervals?? The manufacturer(seller) of the oils made the original recomendations to the vehicle manufacturers. Probably 2500 is a little short but, like the man said it's cheaper than an overhaul and I change mine on schedule even though I don't really believe it.

FYI Mobile 1 -- is the standard oil delivered in new Corvettes