thanks David, I learned a bunch from that. I still havent made the decision to go to synth yet but you make a very compelling case. is there any trugth to the claim that if I go synthetic that I'll have leakage problems?

 

Well, I am no world expert but here is what I have learned over the years -

Back like 10-12 years ago, some manufacturers and engines used seals that relied on the aromatic components in dino oil to make these seals swell. With synth oil, these compounds are almost non-existent and that caused some problems with otherwise good seals back in the dark ages. Modern engines have better seals and if your seals are not damaged or there are no other problems (like warpage or a seal is blown due to clogged PCV valve, etc) just using synth should not CAUSE a leak.

That being said, synth oil tends to be much thinner and has a higher surface tension than dino oil, so if there is a leak the synth will find it faster and more of it will leak out versus dino oil. (You can buy an additive that causes the seals to swell-up; if putting this stuff in your car "cures" the leaks, you just have tired, old seals.) Eventually all engines will start to seep some oil, but this is not what leaves puddles on your garage floor. This is just the situation where it looks "damp" around the gaskets, but oil is not dripping on the ground.

Overall, I think that the benefits to moving parts of the engine outweigh the potential increase in seepage you may see from using synth at the 100k+ mile ranges. Its analogous to a person getting cancer at age 80; if they didn't make it to 80 they would never had cancer, but you can say they are unlucky to get cancer, or lucky enough to live that long in the first place. If your engine dies a premature death, you never see oil leaks. I have a Ford Taurus (teenager beater car) that is a '97 with 183k miles on the clock and it doesn't leave oil drip spots on the driveway, but there is quite a bit of old oil seepage crud on the bottom of the engine. It has only had dino oil in it (well, at least for the time I have owned it which was from 154k miles on). I wouldn't waste synth in that but I do use it in all my other cars and I never had any unexplained leaks on them past 100k miles. Again, just my opinion but I think the bargain synth oil (like the NAPA private label Valvoline) is well worth it for an Acura CL.

My personal rule of thumb is if the car is good enough for me to carry collision insurance coverage, then I use synth oil. Once I carry only liablility, I switch to $1.50/qt dino stuff. Hope all this helps more than confuses you!

 

ok good points now i here that if you used to use or previous owner used to use dino oil but you decide to go synth. will it screw the motor up internally ? i've heard this myth a bunch of times

 

All I can say is that is a total myth. I have switched to synth in the last 3 used cars I purchased (I assumed that dino was used previously) and there have been no ill effects. With my Audi and VW dealers, the "included" maint (oil changes are included during warranty @ no extra charge) is for dino, but they will put in synth if you pay extra $. I use the freebies as an engine flush for like 200-300 miles and then go back to full synth.

This comes from the early days of synthetics when some oils were not fully compatible with dino oils (similar to what happens today when mixing different types of coolant). Today, all oils are required to be compatible with all other similar rated (e.g. "SL" API classification oils are OK to mix w/all other SL grade oils) oils, both mineral and synth. Just read the labels.

Don't worry, you can switch back and forth; just don't go full synth for the first few thousand miles on a brand new engine (unless it comes from the factory with full synth).

 

Had an oil change by the local Acura dealer (who I am quite impressed with they are good people it seems). Found out they are using Castrol Syntech 5W30 in my 2001 CL. Any opinions on this oil?

I'm leaning more and nmore toward switching to Mobil 1 on my next change.


Thanks

 

Castrol Syntec is decent oil; I have used it in the past. My VW dealer used to use this as their "shop" synthetic brand. The bottom line is any full sythetic is head and shoulders better than the best dino oil. Whatever one best meets your budget or what you are willing to spend is what you should choose.

Castrol was the oil that redefined the term "synthetic", as they pushed the legal definition when they started using chemically altered (chemically de-waxed) dino oil. They are all good; the reason I mentioned the NAPA stuff was because if cost was your sticking point, that is the lowest cost synth I have found. Good luck, and remember that as long as you go with a name brand and the correct API designation and viscosity you will be just fine.