Oil Change Intervals

[Dhbridg]

“Otis” is my daily driver. It’s a 1951 Custom Coupe, stock, with a 239 CI V8. I’ve been changing my oil about every 1500 miles. Use straight 30W with Lucas TB zinc. Change filter with every oil change. Am I being too conservative? Service manual (pg 276) says every 3000 miles. Can’t find a previous post on the topic. How often do you change oil in your early V8?

[swedishsteel]

Depends how you drive it--long enough trips so the engine gets up to operating temp and stays there for a good period of time, you can go quite aways between changes. On the other hand, if you just go a couple miles and back most of the time, the engine doesn't get hot enough to evaporate the moisture, which causes sludge and acid, etc. then you need to change quite often, especially if you don't have a filter.

[joe 1950]

Your doing a great job i’ve had my 50 flathead cpe 24 years and always used 30 weight detergent oil mostly quaker state and lucas oil supplement never smoked or used oil or had problems i changed every year in the fall before i put her away for winter i averaged about 12-15 hundred miles a year

[paul2748]

No expert on oil, but with today's oils it would seem 1500 is too conservative, especially if you get the engine up to temperature and normally run it that way for awhile

[ford38v8]

While driving cross country in a vintage automobile, I find it convenient to change oil and filter every other day, and not to forget the zerks, I seek out local grease pits to borrow once or twice during extended driving tours. It's about what's convenient and timely rather than a set number of miles or time.

[Dhbridg]

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Thanks, I’d say my driving is most like Joe 1950 - 1200 to 1500 miles. Shorter trips, engine gets up to temp but no extended driving very often.

[tubman]

One thing a lot of people miss is the fact that Ford called for a chassis lube every 1000 miles on these cars. Most people, then and now, concentrate so much on oil changes that the chassis lube interval is ignored. That is why most of these cars need a full suspension rebuild when being rebuilt/restored. My '51 was purchased new by a couple of bachelor farmer brothers in Hutchinson, MN as their "Sunday go to church" vehicle. As such it was scrupulously maintained by the local garage. I have continued maintaining the vehicle to factory specs and with over 80,000 miles the car still rides and handles very well. I will admit that the latter was helped by the installation of radial tires, Aerostar springs, and a new set of quality shock absorbers.

[VeryTangled]

Originally Posted by Dhbridg

Am I being too conservative?

Hi Everyone. Dhbridg, there are at least a couple of approaches to oil change intervals.

The customary approach is based on miles traveled and conditions traveled in.

This works, but as you've discovered you're in the dark about the answer to "am I doing it right?"

Another approach relies on using science and paying for an oil analysis, preferably multiple tests over multiple oil changes. In post #6 it looks like the full test was under $40 at the time Frank Miller wrote it.

The topic is covered here: https://www.fordbarn.com/forum/showthread.php?t=231478

(adding) For a take on the subject that I found years ago and was educational check this page. But be aware this discussion is not tilted towards flatheads (updated 2002 and talks of oil pressure controlled valvetrains) but still presented some balance I think. Called Motor Oil Myths and Facts... http://www.nordicgroup.us/oil.htm

[Automotive Stud]

I'd rather too much than not enough. I change my oil yearly if it's due or not. If you find you are changing the oil and it still looks fairly clean, then push it to 2k miles and see what happens.

[AnthonyG]

Thankfully I’ve had more toys than I can drive regularly. I’ve done quite a bit of reading on oil life. For most of we old car aficionados the time the oil is in the car is more important than the mileage! I’ve read collectors like Jay Leno & others usually change the oil in their cars once per year even with only a small amount of driving. A car with only a few hundred or even 1000 miles with a filter may look clean but its viscosity parameters are breaking down @ the 12 mo. mark in the car. Sealed in a container from new will last as much as 5 yrs., synthetics longer, but 2-3 yrs for non synthetic & 5 for synthetic is a good rule to be sure! Having said that if you run your vehicle say 6000 miles per year with a filter the modern oil will support 3000 mile oil changes & much more with synthetics, however even with synthetic oil in a stored car, the additives & oil itself star getting contaminated @ the 12 mo. mark so also should be changed once a year @ a minimum.

[Frank Miller]

VT referenced me doing an analysis and in 2019 I met a gentleman who saw my name tag and walked up to me, shook my hand and thanked me for putting real numbers to the debate.
After 8100 miles my used oil was still deemed usable.
I did another little experiment last year when I ran oil that sat 20 years in a motor I had put together and test run. I put 800 miles on that and sure enough the used oil was still usable.

[AnthonyG]

Thankfully I’ve had more toys than I can drive regularly. I’ve done quite a bit of reading on oil life. For most of we old car aficionados the time the oil is in the car is more important than the mileage! I’ve read collectors like Jay Leno & others usually change the oil in their cars once per year even with only a small amount of driving. A car with only a few hundred or even 1000 miles with a filter may look clean but its viscosity parameters are breaking down @ the 12 mo. mark in the car. Sealed in a container from new will last as much as 5 yrs., but 2-3 yrs is a good rule to be sure! Having said that if you run your vehicle say 6000 miles per year with a filter the modern oil will support 3000 mile oil changes & much more with synthetics, however even with synthetic oil the additives & oil itself star getting contaminated @ the 12 mo. mark so also should be change once a year @ a minimum.

[rhphotord]

Just call me crazy or just a compulsive lunatic but I have only about 400 miles on my Av8 roadster and I don't run an oil filter so I've already changed my oil and added zinc additive three times in the last two years. I like clean oil!

[paul2748]

Every 130 miles does seem excessive. I wouldn't classify me as being a tree hugger, but it seems to be a waste of resources. Hopefully, you are at least sending the old oil to a recycling center. In a flathead, zinc additive may be overkill.

Originally Posted by rhphotord

Just call me crazy or just a compulsive lunatic but I have only about 400 miles on my Av8 roadster and I don't run an oil filter so I've already changed my oil and added zinc additive three times in the last two years. I like clean oil!

[ford38v8]

Originally Posted by paul2748

Every 130 miles does seem excessive. I wouldn't classify me as being a tree hugger, but it seems to be a waste of resources. Hopefully, you are at least sending the old oil to a recycling center. In a flathead, zinc additive may be overkill.

X 2! One more thing he's keeping clean is his wallet!

[Karl]

Perhaps - However IMO the best mistake you can make is to change your oil to frequently
In the day Ford recommended 1000 mile oil changes. Yes the oil in the day wasn't as good but most of us that run early V8's don't run oil filters and also probably don't do a lot of long distance motoring as well leading to more gunge build up . Dropping the (detergent) oil is one sure way of getting rid of the gunge. I probably average 1500 mile oil changes. I would prefer to pay for oil rather than a full rebuild . The environment issue is something I hadn't thought of but I guess if I was that concerned with the environment I wouldn't be driving an early V8 that has so much hydrocarbons in the exhaust that people can smell it coming

[rhphotord]

All the oil was recycled. Yes I admit the frequency is "way" excessive but that doesn't make me a bad flathead owner does it? LOL
I've owned the car for several years along with two other collector hobby cars so I drive all three and miles are extremely low on them all. I change the fluids on all three on a yearly basis regardless of mileage, so be it!

[paul2748]

It is recommended that oil be changed at least once a year regardless of mileage, preferably before going into winter storage.

Originally Posted by rhphotord

All the oil was recycled. Yes I admit the frequency is "way" excessive but that doesn't make me a bad flathead owner does it? LOL
I've owned the car for several years along with two other collector hobby cars so I drive all three and miles are extremely low on them all. I change the fluids on all three on a yearly basis regardless of mileage, so be it!

[fordor41]

Originally Posted by tubman

One thing a lot of people miss is the fact that Ford called for a chassis lube every 1000 miles on these cars. Most people, then and now, concentrate so much on oil changes that the chassis lube interval is ignored. That is why most of these cars need a full suspension rebuild when being rebuilt/restored. My '51 was purchased new by a couple of bachelor farmer brothers in Hutchinson, MN as their "Sunday go to church" vehicle. As such it was scrupulously maintained by the local garage. I have continued maintaining the vehicle to factory specs and with over 80,000 miles the car still rides and handles very well. I will admit that the latter was helped by the installation of radial tires, Aerostar springs, and a new set of quality shock absorbers.

I found a lub chart for our '41 in '95(129K miles). Put new king pin bushings in but kept the tie rod ends that were on the car. went by the chart religiously. only part I ever changed was a drag link even after almost 300K miles (2017). On these old cars grease is your friend!

[Charlie ny]

I like Shell Rotella 10-40...once per year....mileage seldom more than 1500....then
make both old trucks 'earn' the oil change.
Charlie ny