This is incredible! Can we discuss this?

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15,082
Location
Canada
Under the topic of 'those with more than 150,000 miles, there is this post: "1968 Nova, 250 six cylinder, 3 on the tree, 2.73 axil ratio, 155HP, max [email protected] RPM, bought new from Joe Moss in Albemarle, NC. Joe was 60 and lived with his mother. He said to run the factory oil for 5000 miles then use straight 20 weight oil. Ran 20W Kendell for first 150,000 miles. Used a quart every 1,200 miles. Put in a Frantz oil filter at 110,000 in 1972. By 150,000 miles, 20W was harder to get, and the store did not have 10W-30, so wound up with 10W-40. When the engine was hot, it ran like it was full of glue. Hummm... Lower fuel mileage, too. I went to an oil supplier and secured some straight 10W. Ran that to 250K miles and about 25 year old car at that point. The straight 10W oil increased my 10,000 mile average MPG by 1.9 MPG to 25.9 MPG. Blow-by and oil consumption started up. Got careless about oil changes. At 325,000 and 30 years, rebuilt the engine myself. About half the compression rings were stuck. All the oil control rings were caked in carbon. The oil control ring drain holes in the pistons were packed with carbon and could not be pushed out by hand and not that easy to drill out. Took 0.040" to clean up the cylinders. Crank miked new. Rod and main bearings had more corrosion damage than wear. She has 361,000 on the clock, now, but the new cam has a 2400 RPM peak torque and is harder to get a load rolling than the old cam. I get whatever 5W-20, yes 20, name brand oil is on sale and PureONE filters. The Frantz by-pass filter gets whatever 2-ply tissue we are running in the john. And, two ply makes a difference!" If I'm reading this right, it puts the debates that occur here on viscosity in perspective. I mean, there are still a lot of people on this forum who think 5W-20 is too thin to run in a modern engine, and those who even think a 30wt-oil is too thin, and run 40-wts. Yet here is someone who got 361,000 miles (580,000 km) on straight 20 and 10 weight oils, in a carburated, heavy, iron straight 6 from the 1960's! I'm aware that the engine was basically trashed at the end, but it still ran, and how many people actually put this much mileage on an engine. I guess my point from all this is that no-one should really worry about running 5W-20 oils, and that it may be a good idea for more people to run them, because the motor will survive, and a person will get better mileage for the life of the vehicle using them. At the same time, they are more expensive, so this savings may be cancelled out. But when they become as cheap and plentiful as 5 and 10W-30 weights....maybe! Any thoughts on this?
 
Messages
4,478
Location
Southern California
GM recommended 20W-20 or straight SAE 30 for <i>years</i> in the early to late sixties. There's NO denying that UOAs posted on BITOG for these 5W-20 motor oils tend to look pretty good, but there is also the FACT that some manufacturers are still hedging their bets by recommending 5W-30 in certain models that may see heavier duty useage - if only for the time being. Some taxi and police agencies that initially embraced Ford's recommendation for 5W-20 in new Ford sedans and cruisers several years ago have gone back to 10W-30 in brand new replacements despite Ford's recommendation. While these cars see strict periodic maintenance, they also see "severe service" in every sense of the term. No particular reason given as to why, but the change of heart by the maintenance crews and/or the agencies' bean counters are at least puzzling. Don't take my comments as personal condemnation of that viscosity. I'm just passing along what I've read here and elsewhere. My own opinion is that for cars that see highspeed use, towing, mountain driving, or heavy useage in urban crawl AND high ambient temperatures in any of the above cases, I prefer a 10W-30 such as either of the Chevron conventionals or any of the ConocoPhillips synthetic blends. If I give up a mile and a half per gallon, no big deal. (nor am I even convinced I'm giving up that much) In both the U.S. upper tier states' and Canada's cold winter climates, though, I'd certainly be looking at a 5W-20 without reservation.
 
Messages
362
Location
Cleveland Ohio
Ok Addguy: remember you are talking about a stove bolt six. These engines were originally designed to be an industrial engine and were without a doubt the toughest engines GM ever made. You could pour sand down the carb and not hurt them. As far as running a thin oil as you seen when you had it apart that there was a lot of blowby. I would much rather protect the motor than worry about 1 MPG. Who knows if you had used a thicker oil maybe it would have gone 450,000 before rebuild
 
Messages
2,387
Location
Chicago area
Also remember that you are talking about a straight 20, not a 5-20. That would make it much thicker than you think until very high operating temps were achieved.
 
Messages
2,759
Location
CarMax
I'm with the above two posters. It's an interesting story but proof of nothing except for one particular case. To me the story illustrates that starting with a heavy duty engine and doing basic regular maintenance with good quality products, you can get a long life out of your engine. 361,000 miles + a very inexpensive rebuild (GM I-6 parts are cheap) = a super low cost per mile.
 
Messages
1,357
Location
California, USA
Why is no one willing to credit the Frantz, rather than the thin oil for that long life? I had a 250 I-6 with three-on-the-tree in a pickup and I think one reason for the survival on thinner oils is that oil temperatures dont get up very high in a slow-turning engine in light duty applications. All the carbon plugging up the rings is because that area gets very hot and thin viscosity solvent-refined oils dont do very well there.
 
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