Would 15 40 synthetic blend be ok for changing the oil in my D8H? I think it is a 1971.
Maybe but I would not do it. If the change in oil causes it to start burning oil like crazy going back to the won't fix it. An overhaul will.
What oil should I use? Straight 30 weight?
15w-40 is fine. Bob
not sure I would use a synthetic blend 15w-40 but would use a conventional 15w-40 as long as meets the API specs. sometimes using full synthetic oil in an engine will cause crank seals to leak in old engines based on personal experience
"semi synthetic" might not mean the same thing that we used to think of as synthetic oil, that is, made from natural gas. Even "synthetic" can be used on conventional oil legally now. Still I wouldn't bother, the oil will get dirty before it will benefit from the life of synthetic.
Would someone please define what synthetic oil actually is. I bought my pickup brand new five years ago. Went through the warranty period with free oil changes at the dealer and no one said a word about synthetic. Once out of that free oil change period I stopped at one of those lube places to check their costs. The expert with a high school diploma tells me the cost which was upwards of $70 just to change the oil and then check all the rest of the stuff. I asked why the prices went so high. The kid says because my pickup has to have synthetic oil. So I asked him to prove it. He pulls out his company manual which shows all Toyota motors require synthetic oil. So I pulled out my owner's manual and it only shows the API grade SN and something else. Now the kid is perplexed and doesn't know what to say other than the company line. I asked him what is the difference between and costly "synthetic" oil for a car and a standard grade you would find in a Pennzoil, Shell or Chevron product. Again a blank stare. So I made a reference to a popular cartoon character at the time and just got in my rig and left. When I got my schooling in fuels, lubricants and coolants while in the US Navy; synthetic oils were formulated for extreme temperatures such as arctic or desert conditions. I had filled many machines going to the North Slope of Alaska with it over the years and drained many more machines that came back from Alaska. The stuff was extremely expensive in those days so it wasn't used in anything operating in above zero temperatures in my area. So back to my original question using different words; are we being scammed by an oil company using the word "synthetic" on a label on their bottle of oil?
I have been running Schaeffers 15w-40 and Cheveron Dello 15w-40 in mine for more than 10 years. both are a synthetic blend I think. I have never had any problems.
Yes. But as far as I understand it, conventional oil that is now called synthetic is much better than it used to be. https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=950311
I've never seen Delo advertised as synthetic. Is it that way now? Thanks for the link. It just goes to show its all in the semantics. Use the manufacturers recommend grade of oil with the specified API grade and you will have no problems. As far as a D8 goes, they ran fine on series 3 oils of the day and any brand name oil sold today is far superior to those old specs. It has been awhile now so I don't know the difference in price between straight grade oils and multigrade but I wouldn't be afraid of running either.
s:// www.chevronlubricants.com/en_us/home/products/by_brand/delo.html?utm_source=bing&utm_term=chevron%20delo%20oil&ut They have a few different 15w-40 oils. Our local Cheveron rep is really knowledgeable, but not pushy. He seams to almost be a oil and lube nerd. Ha. I switched to the XLE SAE 15W-40 a year or so ago.
I don’t see anything in the brochure that says Delo 400 is synthetic.
Delo 400 has always said IsoSyn on the bottle as long as I can remember but I don't think that means it is synthetic. I think it is just there to catch your eye and make you think it might be.
https://www.chevronlubricants.com/en_us/home/products/delo-400-xle-sae-15w-40.html A synthetic blend. I never said full synthetic. Probably just a catchy new word to sell more oil. LOL. Maybe its not the type of oil Tunneldigger meant. Its what I have used in my D8H for awhile with no problem's.