Take a look at the following statements…

■ “I change my oil every 3,000 miles”
■ “I change the oil in my diesel every 10,000 miles”
■ “My fiance burned up the engine in her first car because she did not know to change the oil”
■ “I run 50 wt in my old muscle car because the oil pressure is so low.
■ “Oil companies have conspired to tell us to change our oil more frequently than necessary”
■ “Is synthetic oil really better than regular motor oil?”

What do they all have in common? The answer is that they are things that have been said by yours truly, plus some more. While there will always be theories and debates around motor oil, we’ve come a long way, and here are my thoughts and experiences.

Proper engine lubrication is essential to the life and performance of your automobile’s engine, and there are many factors to consider. Different oils come in different grades. They have different intended purposes; different intended usable lives.

We have always been told that we needed to change our oil and filter every 3,000 miles. For years we just believed it without question. Perhaps it was true in the beginning when refining was less sophisticated and filtration was less advanced. But now, personally, I believe that a decent grade conventional oil has a reasonable useful life of 5,000 to 6,000 miles if you are not racing or towing or driving in dusty conditions. But before we get into a debate, let me relate some experiences that have helped me come to see things the way I do.
In my Lexus ES 300 many years ago, I had the best intentions of changing my oil. I was using a good quality brand such as Castrol or Valvoline. 5,000 miles came and went. 6,000. 7,000. 8,000. I took a job that relocated me and it got even harder to get around to doing it. Finally, I decided to pay somebody to change it for me. Too late. At around 9,000 miles, when on the way to the shop, the lubrication failed and the engine died. With a knocking engine, an otherwise very nice car suddenly became salvage.

With diesel, it is a bit different, since diesel fuel is a less refined petroleum product and has greater lubrication properties than gasoline. My neighbor advised me that he changes the oil in his diesel truck every 10,000 miles. Another friend changes his every 15,000, while changing the filter in between.

Now my 97 Lexus LS 400 with a sweet high performance 4.0 litre V8 engine, I want to make sure I don’t make the same mistake I did with the ES 300. But neither do I want to change my oil unnecessarily just to help the oil companies richer - there are other charities higher on my priority list, like my own family! Now I have gone to strictly synthetic. There are some things to think about when switching to synthetic. What brand should I use? Could switching to synthetic possibly cause harm to my car?

Second question first. Some studies have shown that some cars have developed various degrees of oil leaks when being switched from conventional oil to synthetic. For example, the Porsche 911 was identified as having a particularly hard time. But my Lexus with almost 160,000 mile is doing just fine. And my Suburban with 125k miles does not seem to have any more leaks than it already had.

There are volumes of information on synthetic oil that you can easily find, so I’ll stick to my own opinions for this article. In my own research, I came across some forums where lots of guys are getting their oil tested for various attributes and then posting their findings. What I understood was that not all brands of oil are the same. Some store brands may lube just as good as the best ones up to 5,000 miles, but then deteriorate rapidly from there. In short, I found the greatest reviews for Mobile 1 across the board (Amsoil is another top brand). That is not to say that you can’t get something 10% better by paying 3 times as much. But for a simple guy like me, I like being able to pick up a 5 quart jug of it at Wal-Mart for $23.00, and then being able to drive and drive and drive. How far can you go on it?

Some folks are talking about 25,000 miles on Mobile One and Amsoil (I even remember the old Mobile 1 commercials talking about their 25k mile tests). But I see some saying they use these synthetics and still change their oil every 3,000 miles. Like I said, there will always be debate. However, I think it is actually somewhere in the middle. Personally, I am happy to say that I just went 17,000 miles on my Mobile 1 with a Fram filter. Remember, I drive very conservatively, mostly highway. But if I drove aggressively like in my younger days, or if I was towing a boat, or lots of stop and go, then I might change my oil with fewer miles on it.

The hardest stress on your engine, lubricationally-speaking, is when you first start it up. That is because all the oil has drained to the oil pan. The positive pressure is gone, and only a thin residue remains. Oil pumps are mechanically-driven and work only when the engine is running (unless you have an electric oil pump or primer). So, you want a good quality film coating your internal parts when you first start up. That is another reason I use synthetic.

As an aside, regarding the statement I made about using 50 weight oil, it is true. It was my wonderful 1969 Buick Skylark convertible. The buddy I bought it from had had the engine and tranny souped up a bit; and then he ragged on it! With the 4 barrel Holly carb and the shift kit, she’d chirp the tires hitting both second and third - a lot of fun for teenagers. But sitting at the stop light idling, the oil pressure light would come on. Maybe it was the oil pump, or perphaps there was too much tolerance in the crankshaft and camshaft bearings. But when I added the gear lube, the oil pressure light went out and the pressure gauge rose to a tolerable level.

Back to oil success. There is more than just changing your oil. Think about consumption. Be sure to check it every couple thousand miles. “My car doesn’t burn oil; there is no blue smoke” you say. That is all well and good, but you should still check your oil, because sometimes it can simply disappear. There are a number of variables such as prevalent temperatures, driving conditions, average engine RPMs, ancillary systems and computer settings, and engine design, that could all contribute to possible oil evaporation or dissipation through different ventilation pathways. Simply said, keep it filled within 1/2 quart of the fill line; you don’t want it too low, and you don’t want it over filled. In the case of Manfred the school bus, with a 13 quart capacity, I might add an extra quart. It leaks a little and probably dissipates some too. In the course of a 3,000 mile trip, I expect to use a quart or two.

With the blessing of synthetic oil and some good practices, I am hoping to get extremely long life out of my vehicles.

I hope this helps. Happy trails and all the best.

Michael

PS: I use Mobile One synthetic in my boats, motorcycle, go kart, mini bikes, and lawn mowers.

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