culver

Ahh.. the ol dino vs synth thread. Wow... I think I've read one of these threads since I invented the internet.

I've switched back and forth in almost every one of my vehicles. Didn't notice any more or less oil leaks. There's been a few studies on the subject, but nothing that is extremely conclusive, considered real scientific, and always debatable.

Even the self-proclaimed experts on oil analysis (UOA) admits there's really no difference in terms of engine wear. Since most engine failure is NOT attributed to the lubricating oil, it's attributed to something else (usually neglect, abuse, mis-use, premature mechanical failure). Using synthetic over petroleum based crankcase oil has yet to be proven to really extend the life of average engine to any significance in terms of the main component wear (bearings, rings, cylinders, crankshaft, camshaft, etc). Show me some certified test data!!

Synthetic oil has a few benefits over dino oil. It's flow charactistics are better at lower ambient temperatures. So if I lived in an extremely cold climate, I'd be using synthetic oil and lubricants in my crankcase, tranny, differentials, etc.

Does the cost of synthetic vs dino provide the value or return on investment on extended engine wear or extended miles between oil changes for the average driver-car owner? It does however, provide a nice sense of "I feel better when I put the more expensive oil in my car". If it "feels" better use synthetic. If you don't feel the value, use dino oil. I ran Mobil One and Castrol Full Synthetic for years, and before that ran Valoline and Castrol GTX oils for years, I can say that I really did NOT noticed any differences in engine wear. I use dino oil now. The Lexus dealer uses dino for my wife's IS250.

In my high mileage Toyota truck (over 200K miles) I did notice that on really cold mornings (cold for Phoenix - 30 to 35 degrees F), the old engine would not "rattle" so loud at cold starts when I had Mobil One in the crankcase. Was the Mobil One better for the engine? YES. Is the amount of "better" measureable? - probably not.

That's just my worthless opinion.

This chap is spot on the money. Use syns if you want to pamper your baby, but don't do it for financial reasons unless you really plan to keep your car well over 150,000 miles - probably much much more.

Also...

Since over 50% of Lexus' are leased anyway, this discussion has no bearing on those cars whatsoever. Who in their right mind would make the synthetic investment for a car they plan on turning in in a few years.

Also...

Few folks realize that dino oils have made significant advances in the past 20 years. The dino oil you buy today has a much better formulation than just a few years ago; to such an extent that entirely new wear and service classifications have been created. This small fact is almost entirely overlooked when forums such as these debate the differences.

I get routine oil changes, from routine guys, using routine (yet correct) oil. My cars have no trouble heading well over 100,000 and don't burn more than half a quart between changes. Usually the fenders fall off, or I grow bored of the car, before I get material engine wear. I don't need a better argument for dino oils than that.

I know this is a dumb question, but no where in the owners manual, nor really in the sales brochure, is the AWD system on the RX 350 described. The salesman said it was FWD all the time until extra traction was needed at which point power was diverted to the rear wheels as well. I'm not sure that makes sense.

Can someone tell me how this system operates? Is it full time, part time, like Audi's system?

Thanks