dplotkin

I'll start by saying I've been an oil change obsessive-compulsive since my first car, every 3,000 miles on every daily driver or less if it looks dirty.

I own 8 old cars and change the oil and filter in each every fall before covering them for winter. I'm in the middle of that escapade now.

I'm not the guy I was 10 years ago, changing oil in 8 cars on my back is no fun, the Impala & Corvette are canisters as you know, 10-40 in the armpit.

The 396 Corvette is used the least, has maybe 300 miles on oil I put in exactly a year ago. It still looks as fresh as new. Would you change it?

Dan

Easy Rhino

I'm an oil change geek as well, and I rarely let any of my cars go more than a year without a change, due to moisture absorption concerns.

I'm sure someone more knowledgable will come along.

steampunk c1

300 miles no I would skip a year.

Bluestripe67

Put about 700 more miles on it, then change it. Dennis

SonnyAK

What these guys said! I used to change mine before every winter, no matter what the recent miles were on them...No more...I just make sure I change them at a good regular interval.

856666

I would not change the 300 mile oil either

But I would take the car out for a 30 minute drive to get the engine hot enough to evaporate any moisture out of the oil.

Phil

Tom/99

I change the oil in my cars at 2,000, or once a year.

Powershift

Dan:

I don't drive my 1967 car very much either. I have now gone to every 2 years oil and filter change versus the annual ritual. It seems to work out better for me, and I don't think the car minds either.

My annual mileage on the 1967 is about the same as your 396 car.

If the car was stored outside or in extremely damp conditions (which I doubt you would do), then I might reconsider. Otherwise you should be fine.

Just use a good oil with plenty of ZDDP and a NAPA Gold #1143 (WIX filter) for the Chevy cars with canisters when you do your changes.

Larry

Biggus Blockus

I do every other year oil and filter changes on my 65 Vette and 67 Camaro.

I put about 500 miles per year on each car. Oil reaches full temperature every time the car is taken out. I think thats the key to moisture control. Oil sitting in your sump sitting in your garage is not going to absorb much moisture. It's not brake fluid.

I have gone to once every two years for oil and filter changes and have had no problems. Probably could go even longer with the high quality diesel oil I have been using. Evan after 2 years it comes out looking new.

65tripleblack

I change oil every 5 years/6000 miles, whichever comes first.

BTW: If anyone has documented proof that old oil causes engine corrosion due to acid, I'd like to see it.

survivor66

I'm surprised none of you have mentioned chemical changes of motor oil over time. I've been told by folks I respect that once the can is opened, oil begins a process of "going bad". Whether oxidation or some other process, the appearance doesn't change but protection value does. I don't think this applies to synthetics (which I don't use in old classics). To be safe, I change once a year max even though it's only 300 miles. Why else would typical mfr recommendations say something like x miles or x months, whichever comes first?

Pilot Dan

The key with a classic car especially one that does not see a lot of mileage is to make sure if you are going to start up the motor you get it up to operating temperature and give it a good run. More harm is done when an engine is started and run for a short time in the garage than not starting it at all. If I have to start one of the cars to test or fix something, I always take it out afterwards for a good run down the highway to burn off all the condensation. Pilot Dan

MikeM

Why not just have a few chemical analysis done on the respective cars at whatever mileage interval and take the guess work and opinions out of it?

Godholio

That's how I discovered that an 8,000 mile interval on my Jeep is actually valid. And that Mobil Delvac has enough zddp stuff for the Vette. The last couple of years have been a mess maintenance-wise, but eventually that's my plan. For $25 it's a no-brainer.

KC John

I'm with you on this one. It would probably take longer than most of us have left on this earth to do damage to a car that is driven 500 miles a year. I think some people are over concerned with changing their oil no matter how little the car is driven. I believe a car brought up to temperature every time it's driven and kept indoors that isn't covered with surface rust when the next season rolls around, will be just fine for more than 2 years with the same oil.

jim lockwood

I've had the oil from my GS (avatar) analyzed after every race. Each time the engine has approached the end of its useful life, wear metals (lead, tin, copper, iron, etc) spike upwards. Saved me from ever grenading an engine and I'm sold on the value of analysis.

However, I wouldn't know what to look for to indicate the oil was "wearing out" and was in need of changing. What would show up?

65tripleblack

I would think that primarily low phosphorous levels if oil is in a flat tappet cammed engine.
Elevated H2SO4 levels if a engine is generally started and not driven until vapors can boil off.

Godholio

Blackstone Labs' result sheet shows a whole list of chemicals/metals/etc, along with how much was in your sample (PPM) vs the norm for that type of oil. They also offer a narrative of what they think it means.

I didn't think I had a copy of one of mine, but here's one from my Jeep this summer:


Edit: Before anyone goes crazy on the 10k mile recommendation, Jeep has actually changed the owner's manual to say the same thing. My manual says 8k, but newer ones are 10k. The only mechanical change was an anti flowback valve on the oil filter.

BobT59

For the few bucks it costs, I change the oil and filter in my '59 every year....during which it will see 1000 miles at best...

tubman

Being "geriatrically challenged" as well, I've essentially quit changing oil and filters on my cars. I can't tell you how many years I spent replacing oil that looked exactly like the oil I just took out of the car before it dawned on me that I was just wasting a lot of time and money. Think about some of the people and situations you have known throughout your life; the guy you worked with that just added a quart when it low and his engine went 200K miles? I had a friend that had a former Ford cop car that had over 100k when he got it and would only add a quart if the warning light went on. I could go on and on. So your engine will only go 80K on a fresh rebuild instead of 120K; who will know? The curator of the museum in 2305? In my opinion, changing the oil every year is a pyschlogical decision, not a mechanical one. Do it if you have to; me? I'll concentrate on driving them enough so they get hot on each use.