Synthetic Oil

Interesting, though, how these engines can be so finicky about oil - some do great on synth, others prefer dino... I like dino cause i never go over 2k OCI - I tried more once, and I'm certain it contributed to my stuck rings. IMO, if the oil is darker than coffee, it's well past time to change that crap out..

Darker oil doesn't indicate bad oil. Oil is meant to suspend contaminates, darker oil generally means that it has more "soot" but that doesn't truly degrade the performance unless its beyond ridiculous. What you have to truly worry about the most is if the oil feels gritty or has a lot of visible particles suspended. Soot particles are generally much smaller than the low limit of your filtration medium so it passes right through. Dont expect that to impede oil performance by a large degree.

Synthetic oil is perfectly safe to use in any reasonable condition engine. The problem isn't that it causes problems, its that it can sometimes unmask them. Synthetic oil particles are uniformly sized unlike dyno oil with variable sizes. The large particles can help get stuck in smaller holes and make the car not burn oil so it seems fine, if you switch to synthetic and burn oil thats why - because there was already a bad seal and crappy oil acting as a band aid.

I would go with the recommended oil change intervals, rather than the oil color - although really dirty looking oil should be cause for a change.

Just wondering.. Is it that important to have full synthetic oil on a high mileage car?? I have a 94 Corolla DX that I recently purchased and a 96 Honda Prelude. The prelude I only used regular oil and it has 178k on it and I had no problems with it.. I guess if you baby your car, it's okay.. But I've heard that full synthetic is better cos it protects it for a better engine life??? I just don't know the difference between regular and full synthetic.. I know synth is thicker and it's better for the motor... To me, as long I change oil regularly and replace anything necessary is okay...

Dino or synthetic, the important thing is regular oil changes at good intervals - if you're really concerned about what type/brand of oil, check with the guys at BITOG (bobistheoilguy.com - go to forums) and/or do some used oil analyses.. they're not that expensive and will tell you if you've got excessive wear or anything. (like $10-30 each)

Just wondering.. Is it that important to have full synthetic oil on a high mileage car?? I have a 94 Corolla DX that I recently purchased and a 96 Honda Prelude. The prelude I only used regular oil and it has 178k on it and I had no problems with it.. I guess if you baby your car, it's okay.. But I've heard that full synthetic is better cos it protects it for a better engine life??? I just don't know the difference between regular and full synthetic.. I know synth is thicker and it's better for the motor... To me, as long I change oil regularly and replace anything necessary is okay...

Synthetic is generally used by two different types of owners. The kind that wants to go as long as possible without changing the oil, and the guy who has a performance car. For a Corolla, is is probably going to be for longer oil changes. However, for really cold weather, running Mobil 1 isn't a bad thing. I put Mobil 1 in our Corolla. I'm not exactly sure why. I guess it's cause the wife usually drives it and I don't always get to the oil change in time. I run Mobil 1 in a turbo car that gets changed between 3-4K miles and I run wal-mart super tech in a Mustang. I have different reasons for running different oil in cars.

For the turbo car, it's mostly to protect the turbo, but the car revs out to 7200 RPMs and I drive it hard. I don't push the mustang revs much past 5,500 PRMs, it's a push rod, basic, tough, and I throw regular oil in it. I think I mixed it with a little bit of synthetic for cold start ups, but in the summer, it's all dino oil.

True Synthetic will protect more than dino oil in many cases, and because of the uniform size it and nature of its composition it tends to be more slippery - meaning less friction - meaning more gas mileage, less wear, smoother running. A good oil like mobile 1 is more likely to leave a film on cylinder walls for when you leave the car parked so cold starts have less wear on those first few cranks (initial starting of a cold engine without oil pressure causes over 80% of an engines total wear)

True Synthetic will protect more than dino oil in many cases, and because of the uniform size it and nature of its composition it tends to be more slippery - meaning less friction - meaning more gas mileage, less wear, smoother running. A good oil like mobile 1 is more likely to leave a film on cylinder walls for when you leave the car parked so cold starts have less wear on those first few cranks (initial starting of a cold engine without oil pressure causes over 80% of an engines total wear)

Good points - that is why I switched to using Mobil 1 in my car. I drive it kind of hard at times.