Hi, what is considered normal oil consumption in miles for a street driven 312.

1955 312 T-Bird Warwick, NY

In looking through the 1957 Ford Service Manual, I do not find any reference as to what would be considered any oil consumption parameters and/or at what mileage points an engine would be necessarily disassembled for servicing due to what would be considered excessive oil consumption.  Back in its heyday, some level of oil consumption was considered acceptable and adding a quart of oil between changes was considered normal.  Modern ring technology and advances in engine oil formulations has oil consumption very minimal with no apparent loss of oil even at 7500 miles.
 
Normal is a subjective term and is better described in this case as to what you are willing to live with.  Barring any oil leaks, using one quart of oil in 3000 miles would be my own personal limit.  Anything more than that would have me tearing into the engine assuming I am using this engine as a daily driver.  If just a weekend or Saturday night cruiser, then changing the oil will come much quicker basing that on a time basis rather than if using mileage as the determining factor.  At the very least, engine oil on the older  engines not driven regularly should be changed once per year as oil does oxidize over time.  There are those instances where adding oil over the long haul is simply less expensive than doing a complete rebuild of the engine.  I had a customer with a 390 Cadillac that was complaining about using a quart of oil every 2000 miles.  He only drove that vehicle 2000 miles per year and after explaining the costs of rebuilding the engine to fix that, he was happy just adding and/or changing the oil rather than spending the money to rebuild the engine.  He left happy and relieved that he was doing the right thing.

Lorena, Texas (South of Waco)

😊 Thanks Ted 🚗

1955 312 T-Bird Warwick, NY

Does the road draft tube come into play for oil loss? My car always leaves a couple drops on the garage floor. I assume at highway speeds it will lose some also. I generally have to add a quart or two between oil changes. This is on a motor that was rebuilt about 3500 miles ago.

Durham Missouri

Once I figured out the leaks and removed the draft tube for a PCV system I don’t add any oil. I change oil once a year and have 11,000 miles in 9-1/2years. Engine is spotless inside as I have had the pan off last year as well as the valley cover for the PCV system installation. The draft tube was never wet. I won’t say it uses any oil but it’s negligible. Good luck.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Back when I was running Rotella 15/40W, it seemed like I was adding a half quart every other drive.  Now that I’m using Penn. 10/40WHR, I hardly ever need to top-up (100K mi. on rings/seals).  Go figure.
BTW: Re: adding oil vs. rebuild:  Back in the early 60s, I pumped gas at a discount station.  We sold recycled oil in glass jars for 10 cents-a-quart.  A customer had an old/beat jalopy on it’s last legs that burned excessive amounts (his gigantic blue-cloud trail sure wouldn’t get by today for very long), He kept a 40 gal. drum (with a faucet tap) in the trunk. We would unscrew a cap and fill it up for him.  Was still cheaper than a ring job.

6 VOLTS/POS. GRD. NW INDIANA

I used to use Rotella 15/40 also, went through it like stink. I’m using Valvoline 20W-50 VR1 Racing Oil part #vv211 because of the high zinc content for flat tappet engines; any thoughts?

1955 312 T-Bird Warwick, NY

Guys Ford wanted 20 wt oil, I run 10/30 or 5/30

My last 2 changes have been Lucas Hot Rod and Classic car 10-30. No consumption that I can tell since I fixed the leaks.
 
I have something to add concerning weights an oil consumption. My personal truck is a 2018 F-150 with the dreaded 5.0 which was new for 2018 with plasma cylinder wall coating. It currently has 24,000 miles of combo driving but mostly city. I installed a Ford Performance oil separator in it's first week. It used no oil in the first 10,000 miles. It has since been thru 2 oil use tests conducted buy the authorized dealer I purchased it from along with 2 other trunks in the past. It was right at the limit of 1qt per 3000 miles which was determined by Ford to be the limit by a service bulletin I had a copy of when I went in for the first time both times so no engine replacement was authorized. I really didn't want to have this done unless it was absolutely necessary.
 I've read a lot on the internet concerning this and most had to do with driving habit, PCV valve changing, and the reprogramming of the truck. Ford idea also included a new dip stick with a broader range and a wider gap in the holes. This engine holds 8.8 qts of oil and it had never ever had anything in it other than the MotorCraft 5-20 Semi-synthetic authorized from Ford. With total highway driving this truck gets 22.5 MPG at 70 mph. It's the best Ford truck I've ever had.
After reading so much I decided to follow what a few others did. I changed to MotorCraft 10-30 Semi-synthetic and in 2000 miles it hasn't use any oil. Take the info for what its worth. I believe the 5-20 was for fuel consumption or at leas part of it. Our previous Ford pick up had the twin turbo V6 using 5-20 and never used any oil in 50,000 miles. I just didn't like the truck.
Oil will always be a personal choice normally because of horror stories of the past. I used 20-50 in one car for 15 years and even tho we got good service from it, it was was the worst thing i could have ever done after I looked in the tune-port intake.
20W is not an ez find today and wanting to keep the y-blocks oil passages open and clean is in the for front to me.so changing often is fine along with excellant filters...Sorry for the rant.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

It doesn't matter what type of oil your using, you oil  problem is because of your road draft tube. Make sure you oil return is clean, the oil spots on the floor is the give a way. I run Mobil 1, 15/50 and a zinc additive, change oil every 6000 miles (Change filter at 3000 and add a quart ) Clean road draft each time I change oil. 40,000 on factory rebuilt 292, Engine uses less than a quart every 3000 miles.