IH ONLY NORTH - View Single Post

Swepco · 07-23-2008, 08:57 AM

Craig,

Thanks for your posting and your questions......

First of all, I'm glad to hear that you are using SWEPCO 306 engine oil in your rig - and also glad to hear that you changed the oil after the first 1,000 miles after a rebuild. Most people don't realize how important it is to change the oil within 1,000 miles after a new engine, or rebuilt engine is put into service. New/rebuilt engines are loaded with dirt and metal particles, most of which is too small to see without a microscope.

Back 30 -40 years ago oil technology was not nearly at the level as it was even 10-20 years later. Single weight viscosity oils were normal recommendations back then simply because multi-weight oils had not been developed with sufficient chemistry to work well. I remember back in 1955, my dad bought a new Buick V-8 and was told that the factory fill oil was 10wt oil, for him to drive it 500 miles, then switch over to 30wt.....seems they wanted a light-weight oil to help the rings seat faster, but the problem was that it didn't provide a lot of protection. Back then, all automotive oils were non-detergent oils which would look clean on the dipstick only because there was no detergent or dispersant in the oil to hold contaminants in suspension...if you ever pulled the pan on an engine run with non-detergent oil, you would see a huge amount of sludge sitting on the bottom.

Since you have rebuilt the engine, using modern day parts, it is no longer necessary to "break-in" the engine with straight weight non-detergent oils like it was back when your rig was first built.

You didn't mention what part of the country you are in, but I would probably recommend either the SWEPCO 306 15W40 or the 20W50. If you experience high ambient temperatures in the summer, like we do here in California's Central Valley, I'd probably stick with the 20W50, especially if you work it really hard when you have it out. Otherwise 15W40 would also do a good job for you.

The next part of your post is a little more complicated than what it might seem to be.

If you read the last article I posted about why oil goes bad, you will note that the quality of the base stocks and additives used will have an awful lot to do with the life of the oil (not counting contamination, of course).

With normal use, when overheating is not a factor, nor fuel or water contamination of the oil evident, 5,000 miles is the recommendation for normal oil changes unless you are using an oil analysis program. I've met several "old-timers" in the course of my career who look at (and measure) the condition of the oil by how it looks and smells on the dipstick. This is not very scientific, but they were convinced that was the reason they had 100,000 miles on their engines!

Using a comprehensive used oil analysis program is compared to having a blood test taken on your body.....since oil is the lifeblood of the engine, it will tell you precisely what is going on with the oil in the way of additive levels, metal wear and fuel/coolant/soot contamination. It will also tell the condition of the oil in respect to oxidation, which is the major cause of oil breakdown, outside of contamination.

A 5,000 mile drain interval using Swepco under normal conditions (including light towing) is not unreasonable considering the quality of the product, on a gasoline powered engine. You want to make sure you change the oil filter at the time you change the oil and check/replace (if neccessary) the air filter especially if you off-road a lot.

As far as aging is concerned, unopened containers of fresh oil will certainly last longer than oil in an engine which is just sitting. Used oil in an engine is exposed to air, water and fuel, also to chemical reactions of any material in the oil itself. These factors will all have a result on the life of the oil.

Sorry to be so vague, but once again the "scientific" way to extend engine oil drains is to use an oil analysis program, otherwise you can be playing Russian Roulette with your engine and you might as well be looking at or smelling the oil on your dipstick to determine your drain interval.

Dick Floryanowich

07-23-2008, 08:57 AM	#9 (permalink)
Swepco Oil Moderator Join Date: Apr 2007 Member Number: 207 Posts: 62	Re: Official Oil Recomendations Craig, Thanks for your posting and your questions...... First of all, I'm glad to hear that you are using SWEPCO 306 engine oil in your rig - and also glad to hear that you changed the oil after the first 1,000 miles after a rebuild. Most people don't realize how important it is to change the oil within 1,000 miles after a new engine, or rebuilt engine is put into service. New/rebuilt engines are loaded with dirt and metal particles, most of which is too small to see without a microscope. Back 30 -40 years ago oil technology was not nearly at the level as it was even 10-20 years later. Single weight viscosity oils were normal recommendations back then simply because multi-weight oils had not been developed with sufficient chemistry to work well. I remember back in 1955, my dad bought a new Buick V-8 and was told that the factory fill oil was 10wt oil, for him to drive it 500 miles, then switch over to 30wt.....seems they wanted a light-weight oil to help the rings seat faster, but the problem was that it didn't provide a lot of protection. Back then, all automotive oils were non-detergent oils which would look clean on the dipstick only because there was no detergent or dispersant in the oil to hold contaminants in suspension...if you ever pulled the pan on an engine run with non-detergent oil, you would see a huge amount of sludge sitting on the bottom. Since you have rebuilt the engine, using modern day parts, it is no longer necessary to "break-in" the engine with straight weight non-detergent oils like it was back when your rig was first built. You didn't mention what part of the country you are in, but I would probably recommend either the SWEPCO 306 15W40 or the 20W50. If you experience high ambient temperatures in the summer, like we do here in California's Central Valley, I'd probably stick with the 20W50, especially if you work it really hard when you have it out. Otherwise 15W40 would also do a good job for you. The next part of your post is a little more complicated than what it might seem to be. If you read the last article I posted about why oil goes bad, you will note that the quality of the base stocks and additives used will have an awful lot to do with the life of the oil (not counting contamination, of course). With normal use, when overheating is not a factor, nor fuel or water contamination of the oil evident, 5,000 miles is the recommendation for normal oil changes unless you are using an oil analysis program. I've met several "old-timers" in the course of my career who look at (and measure) the condition of the oil by how it looks and smells on the dipstick. This is not very scientific, but they were convinced that was the reason they had 100,000 miles on their engines! Using a comprehensive used oil analysis program is compared to having a blood test taken on your body.....since oil is the lifeblood of the engine, it will tell you precisely what is going on with the oil in the way of additive levels, metal wear and fuel/coolant/soot contamination. It will also tell the condition of the oil in respect to oxidation, which is the major cause of oil breakdown, outside of contamination. A 5,000 mile drain interval using Swepco under normal conditions (including light towing) is not unreasonable considering the quality of the product, on a gasoline powered engine. You want to make sure you change the oil filter at the time you change the oil and check/replace (if neccessary) the air filter especially if you off-road a lot. As far as aging is concerned, unopened containers of fresh oil will certainly last longer than oil in an engine which is just sitting. Used oil in an engine is exposed to air, water and fuel, also to chemical reactions of any material in the oil itself. These factors will all have a result on the life of the oil. Sorry to be so vague, but once again the "scientific" way to extend engine oil drains is to use an oil analysis program, otherwise you can be playing Russian Roulette with your engine and you might as well be looking at or smelling the oil on your dipstick to determine your drain interval. Dick Floryanowich