oil for '65 t-bird

IMHO for an older American car you can't go wrong with a "fleet" oil like Shell Rotella 15W40 or similar. If you want a synthetic, Mobil 1 Truck and SUV is a similar 5W40. I'd start with a change with Rotella and see if your friend has any issues with that. Upside: Rotella is cheap! but full of detergents to keep the engine's insides nice and clean.

nate

Indeed. Motor oils have a letter following the weight. Every so often they increase the letter to match oils to advances in engines. I remember having to get rid of my 10W30 F oil and start using 10W30 G. Makes you wonder what they have done to oil since the 1960's and why.

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Exactly, that's why it makes me wonder what today's numbers and letters would be for a car from 40 years ago. But do we all agree it would be a

15-40?

A "standard" oil back then was a straight 30 weight, so a 15W40 should be fine.

Once the 15W40 is in there, the owner of the car can monitor temperature, pressure etc. and see if a different viscosity should be used for the next change.

nate

In the heat of So. Carolina, I like Castrol 20W50. Has been good to us for older, higher mileage engines, like the older 68-75 Pontiac

350's/400's/455's and similar years Buick 350's & 455's. Using 10W30, oil lites begin to flicker at idle; switching to Cas. 20W50 would stop both that AND oil seeming to lose viscosity and letting the oil lite come on when the engine heated up completely & lifters began to clack. HTH & good luck. s

As you might imagine, this can provoke a lively discussion and a groan or two on the T-Bird mailing lists (see

In my interpretation, house-brand 10W40 is the modern equivalent of what the owner's manual suggests. Change it about every 3K and use a quality filter (the Motorcraft FL-1A is readily available and competitively priced). The five-quart jug is, intentionally, the right amount for a complete change with new filter.

I run 5W40 or 5W50 synthetic in my '66. The incremental cost of using synthetic is about ten dollars an oil change, a small fraction of the cost of operating such a car.

However, I know the history of my car since overhaul. There is much debate over whether to use synthetics in a "survivor" or older resto whose past use and maintenance are unknown to you. Some people really like the new generation of "high mileage" motor oils in a somewhat worn older car that has the odd leak here and there; cost is about a buck fifty a quart.

That might be a good choice for the extra bottle you keep in the trunk (like most cars of the era, they'll consume more oil than we're used to nowadays -- a quart or so during the change interval is nothing to be alarmed about if the engine seems healthy otherwise).

I would not try to squeeze out the 6,000 miles between changes that Ford suggested was possible, unless I was doing highway driving exclusively. Somewhere in the neighborhood of every 3-4k should be about right.

Have fun with your Bird,

--Joe

What is the story on the engine? Is it an original un-opened engine? Low miles? High miles? Does it consume oil?

If its a tight, non-leaking, non-oil burning engine and you want the very best protection for it, go with a synthetic 10w30 or thereabouts. If its a bit of an oil burner, go with a cheaper non-synthetic, but I'd still recommend 10w30 or maybe 15w50.

Forget those "high mileage" oils- they're just regular oil with some spoo in them to make the seals swell. They'll ultimately shorten the life of the seals though.

If its a fresh rebuild, DEFINITELY go with the best (synthetic) oil you can buy, at least after the intial break-in. Tolerances and clearances in engines from the 60s are almost identical to modern engines anyway- in fact the ONLY real difference is modern engines with hypereutectic pistons (and people frequently rebuild 60s engines with HE pistons now also).

The synthetics have some good points and bad points. Many of them have very good solvent properties, and will remove huge amounts of gum and varnish from older engines. This means sticky lifter problems sometimes go away, but it also means that sometimes you get a lot more oil leakage too.

The leakage issue is made worse by the fact that the synthetics flow a lot better than most petroleum oils, so pinhole leaks that were non-issues turn into big problems.

Personally I have been using Castrol 5W-50 and the Royal Purple 20W-40 synthetics in a variety of older engines and have basically been quite happy with it. The Castrol seems to have more blowby than the Royal Purple stuff, which may just be due to the viscosity.

I did have a problem with a stationary engine that seemed to be held together completely with gum and tar. I tried the Castrol stuff in it, and the oil filter clogged up after five hours of running time, from all the junk that was going into solution. That was a horribly-abused engine before I got it, though.

I'm still trying for 2,500 miles between changes. 480,000 miles on a crappy Chrysler Laser is a good sign I must be doing something right.

--scott

Joe, I usually agree with your advice, but in this case I'm going to have to respectfully disagree with you. Traditionally, a 10W40 conventional oil has a lot of VI improvers which break down with heat and mileage, thinning out the oil, which is less than ideal. I'd stick with either a 10W30 or a 15W40 depending on the requirements of the engine (if it holds sufficient oil pressure with 10W30 that will provide better flow and incrementally better mileage, so its use is preferable IF the engine is "tight" enough to use it.) I basically mistrust any non-synthetic that has a viscosity spread that large (i.e. the numbers before and after the "W" are that different.)

Not a bad plan, IF the engine isn't a leak-monster. Since you say it's been overhauled below, that's probably the best plan for you. One of the big advantages of synthetic is that it doesn't need as many VI improvers to have a large viscosity spread, i.e. a 10W40 conventional oil is iffy but a 5W40 synthetic is probably just fine. This makes life easier on your starter in cold weather without the need to switch between a "summer" (e.g. 15W40 or straight 30 weight) and "winter" (e.g. 10W30 or lighter) oil.

Better yet IMHO than the "high mileage" oils are the "fleet" oils, also known as HDEO's (Heavy Duty Engine Oils) or "dual rated" (will have an API Sx/Cx rating for Spark/Compression, or Gasoline/Diesel) oils. They're cheap, have TONS of detergents and anti-wear additives, and are often available in gallon jugs for less than a regular 10W30. Most common weight is 15W40. Two common brands are Shell Rotella and Mobil Delvac.

Agreed.

Agreed yet again. If the engine is super sludgy inside, you might want to consider using a fleet oil and changing a couple times at even shorter intervals, such as 1000 miles or even less if the oil is getting noticeably dirty before then. A few cycles of this will start to gently clean the insides of your engine, if you periodically have the valve covers off you will actually notice the old varnish deposits softening up and becoming easier to remove.

good luck,

nate

I should be a bit more specific: I had the overhaul done, and other people probably haven't driven the car a total of ten feet since then. (Broke it in on Rotella 15W40 and switched to their 5W40 synthetic, with an interlude of Castrol 5W50 synthetic when it was cheap for a while. Great minds think alike.)

Giving advice to people who've bought a used one (or in this case whose friend has one) is of course rather a lot iffier. Maybe it has a drive-anywhere engine rebuilt with modern technology, maybe a well-preserved original that needs and deserves gentle care; maybe a sabertoothed tiger and a wooly mammoth are slowly sinking into the crankcase.

So what's the story on 10W40 these days? I know it fell into bad repute several years ago (after a long period of being more or less the default substance that people put in their cars), but now it seems to be all over the place again. Better formulations or just short memories?

Cheers,

--Joe

We'll take it in for an oil change and find out what's best, it's just that it was acting funny, like it was going to die, so I thought maybe it was the oil. It's an original engine I think, a '64 actually. The oil has not been changed or put in for about 2 years, but it's been driven very very little, and there is some oil in it still. We just thought maybe it needed some to even drive to a station. Thanks for all the advice, I may come back and look this all over again after the oil change and figure out where to go from there.

Hmmmm. While it could probably stand an oil change, that's not going to be the problem. You're looking at the need for a tune-up (new plugs, cap, rotor, points -- I recommend the solid state Pertronix replacement for them, but I digress), maybe wires);, fuel filter (probably a succession of several of them a few months apart, given the amount of rust often in the gas tanks of these old cars -- easiest to replace with the oil filter off); replacement/enhancement of very aged gasoline from which all the higher volatiles have evaporated; carb adjustment; carb rebuild;, or some "hard parts" engine problems (hopefully THAT one's at the bottom of the list for a reason).

What your friend really needs is a trustworthy mechanic or talented pal who understands systematic troubleshooting of the oldie-but-goodies. Again, the appropriate T-Bird mailing list can help there, a lot.

Best of luck,

--Joe

Oh, and I forgot "vacuum leaks." They call 'em Tee-birds because of all the golf tees inserted in the vacuum hoses leading to one dysfunctional accessory or another.

"But seriously, folks": It takes quite a leak to interfere with a 390 or 428 cubic inch vacuum pump. But it is one of the things to look for (often an older car that has fallen into a state of neglect has several problems going at the same time).

I'm guessing that a '65 does not have Exhaust Gas Recirculation and the balky controls thereof, though California-spec cars might have (they did in model year 1966). It probably does have Positive Crankcase Ventilation, a far less troublesome system but also one that can cause (easily rectified) vacuum leaks of larger size than you get from the interior accessories. A third big-inch vacuum hose serves the power brakes, as it does in most cars.

(Which reminds me that the brakes will become a big part of your friend's life; that can be the next topic, after they get 'er running well enough to consider actually using the car. There are some model-specific concerns there, over and above the general desirability of taking a *real* close look at the system. While they home in on the state-of-tune/driveability problems, I'll dig up an old posting about T-bird brakes specifically, and some related issues.)

Cheers,

--Joe