Mike, I have had a long time experience with synthetic oils. Mobil 1 was the first brand of synthetic oils on the market back in the mid seventies. I have been using it ever since. In my opinion they still make the best product. When the oil first came out, there was a problem with the engine seals shrinking. I personally experienced large amounts of oil leakage in one of my mopar vehicles after extensive use. After a couple of years of perfecting their product, they fine tuned the formulation to fix the gasket leaking problems. I can't speak for other manufacturers. The way I look at it, not only does the synthetic oil cut down on wear, but it also saves me time and maintenance. I have always changed my conventional dino oil every 2 to 3 thousand miles. With the synthetic oil, I have extended that interval to what new car manufacturers recommend these days, 7500 miles. Since Mobil did at one time say that they recommended up to 25,000 miles between changes, I feel perfectly safe with the 7500 mile interval. (I did think 25,000 was a bit extreme). There is only one instance where I would not use a synthetic. The reason being is that it lubricates so well, that it could be a problem during a break in period. When I rebuilt my 440, I initially put synthetic oil in it. That was a a mistake. It kept smoking for a thousand miles. The rings would not burnish and break in properly due to the synthetics high wear protection. I drained the oil, put conventional oil in it and the smoking stopped within 50 miles. After 2000 miles with the conventional oil, the synthetic went back in and it has been happy since. It will go 7500 miles without adding a quart and is leak free. I also use synthetic in my Harley. It gets a heavier weight because the tolerances are looser and because it is air cooled. In fact I even use the same oil in the transmission. Have for the past 10 years without any problems. For a newer car like my wife's 2001, I use 5W-30 or 0W-30. It improves gas mileage and the closer tolerances are designed for this weight. If you look at the service ratings, synthetics have the highest API ratings. They always exceed the latest tests. All of the expensive high performance vehicle manufacturers recommend Mobil 1 exclusively (Viper, Corvette, Ferrari, ...). John Mike Pittinaro wrote: > > have a question. What BRAND of oil does everyone > > prefer and/or recommend? I have a 1970 LeBaron 4 Dr. > > Here's my 2 cents, and I say this with the disclaimer > that there are probably as many oil and filter > routines as there are people on this list. I'm sure > somebody out there mixes in a flake of saffron into > their oil and does a hindu chant. Whatever. > > I don't use synthetic, #1 because it costs a ton and > #2 because I don't think the benefits for my 67 > iMperial are that much more than using a good > conventional oil. Synthetic oils leak more, so unless > you have a newly redone engine with nice, tight seals, > you will find more leakage. This may not be a major > concern- heck, you may even appreciate the perpetual > front chassis lube. But, your oil consumption will > increase as a result. I have also HEARD (and take > this with a grain of salt) that synthetic oils do not > cling to metal parts as well as conventional oils, so > cold starts can be more damaging, esp with engines > with large clearances. The newer synthetics may not > have this problem. > > Bottom line: I would use synthetic in a new car or > with a rebuilt engine. Maybe I would use it also if, > like D^2, I drove my Imp like a bat out of h*ll every > time I took it out. Otherwise, I'd stick with Dino > oil. Personally, I use Catrol 10W-30, or 20W-50, > depending on the engine and the conditions. I change > oil once in the spring and once in the fall, > regardless of miles, and I usually only have 3000 or > 4000 miles MAX between changes on my old cars. My > Imperial has only a tick over 51,000 miles, so 10W-30 > goes in at the fall change, and 10W-30 in the spring > change but I top off with 20W-50 during the summer and > 10W-30 in the winter. I like Napa/Wix filters the > best but the Purolator Pure1's are decent too, based > on some testing I have read on them. I stay away from > Fram. > > I also have a Volvo 122 that I use 20W-50 in all the > time, as it has 200,000+ miles and smokes a bit, and > the oil pressure sometimes gets low. > > ===== > --Mike Pittinaro > > One point eight litres > Stromberg carburators sing > Loose nut at the wheel > > __________________________________ > Do you Yahoo!? > Yahoo! Finance: Get your refund fast by filing online. > http://taxes.yahoo.com/filing.html >