Another oil thread....bear with me

[brick_and_motor]

I am probably over-thinking this but I wanted to put this quandary out to you all for collective opinion. The first thing I'm going to do on my '98 S70 NA is an oil change and I'm debating what oil to use.

My '98 V70 GLT has recently had its second oil change (I changed it when I bought the car in September and then again in January after ~3K miles). Both times it received Quaker State (Pennzoil) 10w30 dino oil because both times that was the special at our local Advance. Now, when I drained the oil in January, it flowed out golden and smooth. I thought this was pretty neat that it appeared to hold up nicely between changes.

The next day, I changed the oil in my '02 VW Golf GL. The oil change intervals were the same (3-4 months and ~3K miles) but in the Golf I used Kendall GT-1 5w30 semi-synthetic for the previous change. However, when I drained the oil out of it, it flowed out blacker but still smoothly. There is very little difference in driving conditions between the two cars with just a slight nod to the VW for more highway driving. One caveat is that the VW uses/looses ~1 quart between changes so it had been topped off prior to changing.

Both cars have roughly the same miles (143K) and use Purolator Classic oil filters rated at 97.5% efficiency.

So to my question: which oil do you think is performing better? Specifically, is the Kendall oil with its darker color, doing a better job of cleaning out the motor and preventing build up of deposits; or is the QS performing better by appearing to break down less over 3K miles?

[850 LPT]

I agree you are overthinking this

You are doing the right and most important thing, which is to change the oil at 3k. This is a good interval if you are using dino oil.

But please make sure you use OEM quality oil filters. I think Mann filters are what most people use, I know I do. Do some research here on the differences between these and lesser quality filters, I'm not sure on Purolators. It's mainly about the lack of a proper check valve that prevents drainage from the head if I remember right.

[tryingbe]

This is the only real test. Color of the oil doesn't mean much. I use AMSOil since I can get it for $4.5 a qt.
http://blackstone-labs.com/

[brick_and_motor]

I agree you are overthinking this

You are doing the right and most important thing, which is to change the oil at 3k. This is a good interval if you are using dino oil.

But please make sure you use OEM quality oil filters. I think Mann filters are what most people use, I know I do. Do some research here on the differences between these and lesser quality filters, I'm not sure on Purolators. It's mainly about the lack of a proper check valve that prevents drainage from the head if I remember right.

Re the filters, Purolator owns Mann and it's no orange can of death like the FRAM. Can't say for certain they are identical, but I do know that Purolator makes a quality filter. That said, now that I have 2 Volvos and will be selling the VW, I will purchase the 10 pack of Mann filters from FCP currently on sale for $47 - can't beat $4.70 a filter.

[benpineapple]

I used to use purolator filters, but they're kind of a hassle to instal and remove. Not a lot of side access on the P80 filters. I K&N filters, because they have a lug on the end to easily remove with a socket wrench.I also had a purolator randomly get frozen on my block, which was odd. Could have been user error rather than poor filter components, but there's no way to know for sure.

Here's a thread documenting it, including a fantastic oil strap tool that makes P80 filter removals a cinch.
viewtopic.php?f=1&t=78771&p=423761#p423761

[j-dawg]

if your oil comes out looking the same as it went in, that would almost be more alarming to me than if it didn't. never had oil come out of any car looking anything but dark brown (or black out of my diesel Mercedes).

[theWIFES_S70]

I will purchase the 10 pack of Mann filters from FCP currently on sale for $47 - can't beat $4.70 a filter.

Uhm, you all should probably check out the Rockauto closeout price right now...

Ordering 10 right now...

[rspi]

... that was the special at our local Advance...

If it's not good for your engine, the "special" can cost you more with engine repairs.

Turbo = full synthetic.

I'm with tryingtobe, if you plan to keep the vehicle, get your oil tested.