I get a discount at Car Quest, so I spent some time asking the guys in there about who makes their CQ brand stuff. Turns out their oil is made by Valvoline and their filters by Wix. I did my last oil change with CQ premium synthetic 5w30 oil (I routinely have to start my engine at -10deg F or colder) and the CQ premium filter for 39.99 after a 10% discount. Even without that discount it would be an awesome deal. I noticed a slightly lower oil pressure at hot idle on the dash gauge, but the engine was noticeably quieter at all temps. It's only been about 1000mi so hard to say about the long term benefits, but it sure starts a lot better when frozen solid and warms up a good bit quicker too!

Only drawback I've found so far is now my oil filter adapter leaks, but I kinda saw that one coming since I just got the jeep (99xj) with 106K on it and it was run on dino oil up until I got it. Luckily I've done that o-ring change before so I still have all my special tools and know exactly what it takes! Apparently switching from dino to full synthetic does in fact cause leaks sometimes. I guess the CQ(valvoline) full syn oil has a good bit of detergents or something in it. I may try some lucas full synthetic next time since they supposedly have less detergents. Anyone ever try Lucas full synthetic?

Ooops, forgot to list my junk input: it had a mastercraft filter on there (and no doubt cheap dino oil of unknown weight) cuz I found it at a ford dealership and it was knocking slightly during the warm-up period before I got rid of that. With the CQ premium (Wix) filter on there and the CQ (valvoline) full synthetic oil, it sounds a good bit healthier, so I'm now wary of Mastercraft filters. Plus it self destructed (filter) when I went to unscrew it so that was a PITA.

 

Interesting story! Do you know if CarQuests's WIX filters are built-to-spec or simply rebranded?

Well you spotted the detergent issue, but think about it a little more. The reason from dino to a modern synthetic can cause leaks is really "switching from a low detergent dino with an existing sludge problem to a synthetic with high detergents". There is such a thing as a high-detergent conventional oil btw. The diesel oils need extra power to clean up soot. The leaks appear when the detergent blasts build-up off of worn seals.

You can switch to a low-detergent synthetic if you want, but you'll still have a sludge problem, and your seals will still be toast. It'd kind of be like saying "man, I used to wash my underwear with only water, but since I switched to Tide that zit on the inside of my leg is getting chafed! I think I'll just use Febreeze instead"

 

bottom line: there is plenty of info out there on oils and filters. Use what you want .change your oil when you want. If you have problems, you have problems. Whose to say your wrong if you don't have a problem using a certain oil or a certain filter. best of luck

 

Either you have (had) deposits plugging the leaks as Salad mentioned, now cleaned away by the detergent, or you had some minor voids in the seals that the synthetic oil's smaller, more uniform molecules sneak past where the dino oil didn't.
I have the latter problem with my Northstar. If I run Synth I get leaks out of the case half seal and oil pan. Dino oil does not leak. Switch back to synth and it leaks again. Back to dino and it stops. I've not had that problem in other motors, but this one has an o-ring type seal instead of a gasket on the case and pan. Same as your filter adapter. I suspect that's the difference.

 

thats good info

 

yeah, to be honest I'm OK with the leaking cuz it's showing me what seals I need to replace. I plan on making this one last a good while, so cleaning out the sludge and replacing the old seals is a good thing in my book! I thought about finding a low detergent synthetic to start with, but I decided it wouldn't be a bad thing to know from the start if I had old failing seals.

As for whether the Car Quest branded Wix filters are the same spec as Wix branded ones, the parts guy in CQ told me they were identical. I've never cut one open to see, however, so I'm not positive. That guy's always been pretty straight with me though so I'd be surprised if he was fibbin. I think I remember seeing a pic where a guy cut open a CQ premium wix filter next to a Wix branded one and it was identical internals. I know Car Quest sells a standard and a premium filter for the 4.0 engine, both made by Wix, at a slightly differing price which are comparable to the Wix branded prices. Maybe next oil change I'll cut into the one I take off and compare it to the pics you can find for a premium Wix branded one. If I do, I'll be sure to post it on here.

 

Car Quest premium, Napa Gold, and WIX branded, use a silicon gasket. When you look through the holes you will see an orange redish gasket versus their regular black gasket. The silicon does not harden with use like the regular rubber one, thus extending service intervals.

 

#1 thing to avoid if you want an engine to last. No modern oil is going to "break-down" as the commercials say, you change the oil to remove the dirt & unburned fuel, nothing more.