1) SOME contaminant is removed from the system – whatever was mixed with the liter of oil you removed,

2) You give the additive package a boost with the new oil.

3) You move the viscosity of the oil back in the direction of “new”, whether it has thinned due to shearing or thickened due to oxidation and burn-off.

So, I see nothing wrong with this approach. Obviously, at each filter change you’re also losing some oil that must be replaced, so you’re performing this same function at each filter change, just with a lesser amount of oil.

Theoretically, this could extend your oil change interval even beyond Castrol’s recommendation, but, I am not personally recommending you do that – at least not without solid evidence that the oil is still in good shape.

The “poor man’s oil analysis” that you used from “The Motor Oil Bible” is very useful, but it’s not a perfect replacement for an oil analysis, so just be careful you do not rely TOO heavily on the information gleaned. It’s useful, but not perfect.

I’ve sent you the download link by email. Enjoy the book. Sorry for any trouble.

However, the temporary fix I’ve implemented seems to have given access back to this other user. Try logging in again and see what you get.

Again, sorry for the late reply.

I am incredibly sorry that you’re having trouble getting access to the specs. I had just taken care of your login when I read this post – however, it’s looking like you must have gotten in with your old login info, which means the new login info I created was unnecessary – sorry. I was just responding to your email.

As for this new problem, as best I can tell it has something to do with the latest WordPress update which has caused some issues with my database integration. I’m working on it right now, but I haven’t been able to solve the issue.

I HAVE implemented what I believe will be s short-term fix which should allow you to access the data. Try logging in now and give it another shot. See if it works for you. If it doesn’t, clearing your browser cookies/cache, restarting your browser and/or restarting the computer to “clear things out” and start fresh.

I’m away for the weekend for my son’s gymnastics meet, so I may have trouble getting back to this before tomorrow night. Hopefully, this temporary fix will do the trick for you.

Very sorry for any inconvenience.

Low temperature testing parameters are different for each viscosity grade with testing done at anywhere from -35 degrees C to -10 degrees C in terms of “cranking” and -40 C to -15 C for “pumping”.

Don’t know if that helps or not, since I’m not entirely sure your question.

Sorry for not replying sooner. I do not agree with their assessment. Although it certainly is possible that the 5w30 oil they put into your engine will protect adequately, and Schaeffer is a pretty good quality oil, the explanation that “all the cars are going to 5w30 now” is bunk.

MANY vehicles are moving to 5w30 and even 5w20 or 0w20 oils, but ALL of them are not, and there ARE situations where this might not be the best option, especially for any high performance engines that you want to last for a long time.

Unless you are specifically concerned about getting enhanced fuel economy or are looking to get that last little drop of extra performance out of your engine (which a lower friction 5w30 oil will likely provide), I do not believe that 5w30 was the best option for your engine. If it were me, I’d stick with 5w40 or possibly synthetic 0w40.

Again, that doesn’t mean that the 5w30 is inadequate. It may do a fine job. I’m just of the opinion that, unless you have solid, logical reasons for doing so (and there ARE, sometimes, good reasons), I wouldn’t disregard the manufacturer’s viscosity recommendations so quickly.

Oh, wait, there are none. I guess they’ll just have to make due with my “crappy” implementation. Cheers.

As a general rule, I try to stick within one viscosity grade of the manufacturer’s recommendation. So, for instance, if a 5w30 is recommended, I’d stick between 5w20 and 5w40 – 5w40 for better high heat protection, 5w20 for better fuel economy – you decide which is most important to you.

If you’re driving in severe cold, you should stick to he 5w or even drop to a 0w rated oil. Otherwise, if the vehicle never sees cold temps, you could easily use a 10w or even possibly a 15w, like 10w30, 10w40 or 15w40.

It all depends on what you’re looking for. But, unless you really know what you’re doing, I wouldn’t stray too far from the original manufacturer recommendations.

Sorry I can’t really be of more help.