Originally Posted By: lexus114
ok,i respect your view here.i think it simply comes down to,do you want your motor to outlast your vehicle x2,or just get a normal service life out of it and move on.
This is what I strive for. I also change transmission fluid on a regular schedule, and I have used synthetic ever since it has been available.. I change the gear oil in manual transmissions, synthetic also, on a regular schedule. On vehicles with rear wheel drive, I change the axle lube, synthetic, on regular schedule. I am thankful that I have never had an engine or transmission failure. I lost the differential gear on a new 70 Camaro because of a factory defect. I have my daughters and son in laws doing the same thing with their vehicles.
I do not know what a normal service life is. I know that 2/3 of vehicles in use in the USA, not counting commercial vehicles, have over 75,000 miles so normal has to be more than 75,000. A guess only would be around 125,000. I expect and count on a minimum of 200,000 for engine, transmission, and axle. I no longer drive up to 70,000 miles a year so they also last longer, time wise.
I was getting over 100,000 on new vehicles in the 1960's, 1970's, and didn't go to synthetics until 1988. I can't say that synthetics extended my engine life by an average of Xthousans miles because I never wore an engine or transmission, or rear differential out. I can say that engines run smoother(difficult to qualify), run with no engine noises, start readily in even the coldest temperatures of Ohio and Michigan that I have been subjected to, no seeps, leaks, or use of any kind. I know that with synthetic my engine is protected from extremes that I will probably never see, but I like that it is there. I also know that sludge, varnish, and other deposits are virtually nonexistent. I know that with synthetic my keep/trade has moved up from about 125,000 to an average of about 185,000. This is based, primarily, on confidence and overall "feel" of the engines under load. That I have two daily use vehicles with 208,000 and 301,000 miles, I attribute to synthetic engine oil, transmission fluid, and gear oil.
I think today's engines are better than earlier. Engines are also more high tech than ever. What is a normal "economy car" engine today was a super race engine a few years ago. My daughter's little economy college car, with all the bells and whistles, had a 4 speed automatic and a DOHC, 16 valve, aluminum head, SPEFI, high RPM engine. Low RPM, in block cam, push-rod, 2 valve engines are getting to be fewer. Where I live, these engines are affectionately called "Bubba" engines. I have a big Bubba truck and a little Bubba car.
I can't see myself ever using anything other than synthetic in oil, transmission fluid, and gear oil. I can't think of any way to justify the use.
