vince@fluke.UUCP (10/10/84)
As a confirmed Mobil 1 user who has used it for over 70,000 miles, starting shortly after the product was introduced, I would like to add my 2 cents worth to this discussion. At the time I started using Mobil 1 I had been doing research into Amzoil and Eon-11, the only other synthetics readily available. The information that I had studied at the time indicated that there were two different chemical bases used in synthetic oils. As I recall, Mobil 1 uses a different base from Amzoil (Mobil 1 has never contained any graphite). However, there was no evidence at the time to support that one was any better than the other. I chose to go with Mobil 1 because I felt that they would be a more reliable source (which they have been) and because I felt that as a giant oil company, they were more likely to have researched their product more thoroughly. Mobil almost destroyed their synthetic oil market through a series of advertisements that oversold the benefits of the oil without giving adequate warning of the disadvantages. Some of the claimed advantages (all true, but only under controlled conditions) were reduced wear, greater power, greater gas mileage, lower oil consumption, and longer oil change intervals. To best realize these advantages it is necessary to start using Mobil 1 in an engine immediately after an extended break-in period of 5 - 25K miles. Depending on the condition of the engine, it is ok to start using Mobil 1 at mileages up to about 70,000 miles. People who fit this category who tried Mobil 1 were probably not unhappy with the results, but switched back to their old oils after noticing how expensive Mobil 1 was. The people who were really unhappy were the ones who's engines had lots of wear, and in some cases, who's engines were destroyed by blocked oil passages. There are two characteristics of Mobil 1 that caused the unhappy reactions that these people had. First, Mobil 1 being a synthetic, has a stronger film strength than conventional oils. This allowed Mobil to create a thinner oil which is capable of protecting parts from wear as well or (actually) better than other oils. While this is a great benefit in a tight engine (reduced friction, greater gas mileage, greater power, etc.), it leads to extreme oil consumption in a worn engine. The other characteristic is that Mobil 1 synthetic has natural detergent and/or solvent properties. This is a benefit in a good engine in that it prevents build up of sludge and varnish. However, in an old worn engine it has the tendency to dissolve the old deposits, freeing large chunks of sludge which may become lodged in oil passages, leading to an engine failure. There isn't much hope for the people with old sludgy engines, but for those of you that have engines in good condition, with under 50,000 miles, you might want to reconsider Mobil 1. Earlier, I mentioned that may people with moderate wear on their engines tried Mobil 1 but quit. That was because the original Mobil 1 was so thin that oil consumption was excessive even in engines with moderate wear. Without checking back, I think the original viscosity was 5W20. However, sometime in the last couple of years Mobil raised the rating of their oil to (I think) 10W30. (If I got that wrong, I'm sure we'll hear about it). To my knowledge, the original "thin" viscosity is not available now. One warning to people considering a synthetic for a new car, research has indicated that engines will not break in properly on a synthetic (I think it had to do with the rings not seating properly). All new cars should be thoroughly broken in on conventional oil for at least 5,000 to 10,000 miles. Another warning rarely stated is that if you chose to go to an extended oil change interval, you should be aware of the possibility of acid build up in the crankcase. This is a result of sulfur in the blow-by gasses creating sulfuric acid. Not so surprisingly, this acid can be a very significant source of engine wear. Oils contain acid neutralizers in them as an additive, but they are consumed with time. I try to avoid acid problems by being sure to add sufficient oil frequently enough that there are always acid neutralizers in the oil. With my present driving habits and engine condition this equates to adding 3 quarts and performing a complete oil and filter change once per year (at about 10,000 miles per year). So what has my experience with Mobil 1 been? I started using Mobil 1 in my '72 Opel w/1900 four cylinder at about 65,000 miles in 1977. I realized that the car's mileage was somewhat high to begin using a synthetic, but as a student, I felt that I would not soon be able to afford another car or major engine work. I was counting on the synthetic oil arresting the wear level on the engine at that point. Initially I consumed about 1 quart per 800 miles, and that consumption gradually increased to 1 qt. per 600 miles before I rebuilt the engine at 93,000 miles (more on that to follow). This was using the original "thin" Mobil 1. I did notice a slight increase in power and gas mileage. During this period, I did not made a practice of changing the oil, but only the filter at about 6000 mile intervals. Because of the high consumption I was experiencing, there was always fresh oil in the crankcase. Never did I experience any kind of internal engine failure. At 93,000 miles I found I had the time (quarter break) and money to perform an engine rebuild and so did so. What I found when I tore down the engine was very encouraging. There was no sludge to speak of and only a little varnish in the valve cover. Other than that the engine was squeaky clean. I measured wear as I disassembled things and found it to be quite within reasonable margins. The shop I took the head to recommended that I replace the cam shaft bearings. As I was starting to run short on money and knew that I would be using synthetic oil again, I declined to replace the bearings. I replaced all other main and rod bearings and the rings. I did not bore the cylinders or replace pistons. Today, at 146,000 miles my Opel is running strong. Compression is good and oil consumption is about 2000 miles per quart (using new "thicker" Mobil 1). I have not had any reason to have the engine apart in the last 53,000 miles. My gas mileage is great, and is the best its ever been. I get 25 MPG around town and 28-32 MPG on trips. This may not be all that great compared to today's cars, but this car only got 23 MPG at best when I bought it at 65,000 miles. My apologies that this posting is so long, but I thought with all the interest shown in Mobil 1, that a complete case history would benefit many of you. Good luck to all of you who decide to try Mobil 1 yourselves. Craig Johnson John Fluke Mfg. Co., Inc. Everett, Washington uw-beaver! \ decvax!microsof! \ ucbvax!lbl-csam! > fluke!vince allegra! / ssc-vax! / As usual my opinions are my own and have nothing to do with my employer etc.