I have gone 12 months before changing oil on my 3.0 Sport Wagon...I just don't hit the mileage as my CTS is not my daily driver...no signs of oil burning and I've not read of any 3.0 owners experiencing the timing chain issue...
I'm currently at 6months and about 2500 miles since my last Mobil 1 oil change...
are you still experiencing issues after your spark plug change???...that is a strange one...
Yeah I got it down to a science now to fill up at Costco. I have been trying to get better, but I still end up wasting about 5 seconds on average and there's nothing can do about it.
1. While waiting in line, put on my mask, glove, get wallet out, get costco card out.
2. Put all trash in trash bin.
3. Pop the hood, lower both front windows.
4. When I get to pump, get out, go to pump, slide costco card in and out, when approved, stick in credit card with chip
5. While the chip is being authorized (now have to leave it in there for a few seconds), push open the gas lid and open the cap and hook line on the hook.
6. Remove credit card (must do the previous task within like 5-7 seconds, if you leave the card in too long it freezes and you have to start all over, wasting more time), put card in wallet, grab pump, hit grade, put wallet in pocket while machine sets up the correct price, then enter pump and click on the lever. I usually lose about 2-3 seconds here waiting for the pump to reset and get ready to pump.
7. Open hood, take dipstick out, wipe, reenter to check, stick in, close hood.
8. Reach in through passenger open window grab trash bin, empty trash, return bin
9. Wait until gas stops, remove pump and return, close cap, throw away glove. I lose another 3 seconds throwing away the glove, no matter how fast I try to do this, the receipt has already printed in advance when I get back to it from the trash.
10. Remove receipt
11. Put into wallet while walking to driver door
12. Enter and drive away
checking your oil level that way may not give you a proper reading...aren't you supposed to wait 20 minutes or so (I check after the car has been sitting like first thing in the morning after sitting over night) so the oil can get back down into the sump???...
Actually short trips are worse on the oil/filter than long trips. Even in hot & dry California, there is still condensation getting into the oil when you only go on short trips. Like others have said, change it at the reccomended frequency or once a year. An oil/filter change on schedule is a cheap way to help keep your engine happy for many years to come.
when I get my oil changed, after filling, the guys usually check my air pressure, air filter, look around underneath...brakes, etc...then take a reading at the stick...they also know about how much they are supposed to take out and how much to put back in...
since you fill at Costco, do your Costco pumps not have the chip reader where you can just tap the chip part of the card to the reader above (or near) the inert slot bypassing inserting the card ever?...touch the spot until it beeps and you see the green lights...