i just purchased a new 2004 CTS 3.6 VVT.....and only has 22 miles on it... when would be the good time to change my oil??? synethic or regular??? and what gas do you guys use?? premium or regular?? or MID??? sorry im a noob... :hmm:

i just purchased a new 2004 CTS 3.6 VVT.....and only has 22 miles on it... when would be the good time to change my oil??? synethic or regular??? and what gas do you guys use?? premium or regular?? or MID??? sorry im a noob... :hmm:
follow the manual
regular gas and MOBILE 1 Synth

follow the manual
regular gas and MOBILE 1 Synth

I take it that's a motor oil available only in Alabama? ;)

Stay with Synthetic unless you own an oilwell and don't want the added gas mileage. Change it when the system tell you. press your info button and look at oil life.... don't bother before, waste of money...

wr

As others have mentioned...stick with a full synthetic like Mobil One. The manual states to use an oil that meets GM spec GM4718M, and that's ONLY a full synthetic. A few other companies also make full synthetics that meet this GM spec..Valvoline for one does I know.

BE CAREFUL! Some Cadillac dealers...like the one I bought my CTS from, DO NOT use an oil that meets this GM spec. In my mind, that should be grounds to revoke their franchise, but just make sure when you have it changed that they understand that you will accept nothing except an oil that meets the GM specs called for in your owners manual. And follow the Ronald Reagan School of negotiation...trust, but verify.

As for fuel...the 3.6 liter engine in the CTS is designed to run just fine on regular 87 octane unleaded. I tried a tank full of 93 octane premium one time..and noticed no difference in performance or fuel economy. Save your money and use 87 octane regular

higher octane has a negative effect on an engine designed for lower octane.

is this true????? on CTS??? i beileve 3.6 VVT runs better and stronger with premium

is this true????? on CTS??? i beileve 3.6 VVT runs better and stronger with premium
car achieves maximum power just before it's about to lean out. Hence lower octane. Higher the octane further away from leaning out.
I'm not sure how much of impact higher octane will have on 3.6 but 3.6 doesn't seem to benefit at all from running high octane gas.

I agree completely...but, trust me, discussions on religion and politics will generate less argument then "gas and oil" topics!

And follow the Ronald Reagan School of negotiation...trust, but verify.

I'm going to need to know since my dealer is one that doesn't offer Mobil 1. If I buy and ask them to use my oil, then how can I tell it was done. Is the color different?

I'm going to need to know since my dealer is one that doesn't offer Mobil 1. If I buy and ask them to use my oil, then how can I tell it was done. Is the color different?


No, you can't tell from the oil color. If you bring in your own oil, just stress to them the importance of using ONLY that oil to you. Also, the 3.6 engine takes 5.6 quarts of oil with a filter change..ask them to return the extra to you, just in case you should need to top it off sometime before your next oil change.

I'll be getting mine changed at an oil change place near my house that I have used for years. I can watch them changing the oil from the waiting room. That came in handy while getting my Corvette's oil changed on more then one occasion. I always maintained and checked the tire preasure myself..I knew it was dead on at the recommended 30 psi. I saw a new employee putting LOT's of air into one of the tires. Since I knew it didn't need it..I stopped him..and asked what he was doing. He said he was filling it to 45 psi, which is the max preasure listed on the sidewall of the tire. He had never heard of the manufacturer recommended presure on the sticker on the door jam..and I shudder to think what he had been filling tires to in the time before I enlightened him.

car achieves maximum power just before it's about to lean out. Hence lower octane. Higher the octane further away from leaning out.

What does the grade of gasoline have to do with an engine leaning out? The only time fuel makes a difference on running lean is with oxygenated fuels, and even then modern cars will adjust the A/F ratio to compensate. Higher octane fuel does burn a bit slower than lower grade, but it's debatable as to whether that has any detrimental effects on power in the real world.

I agree that there's no point in running premium in an engine designed for regular. In fact, I always ran regular in my 2000 Z28 even though premium was recommended. Sure I suffered a bit less power at WOT, but I had plenty of power to waste :).

What does the grade of gasoline have to do with an engine leaning out? The only time fuel makes a difference on running lean is with oxygenated fuels, and even then modern cars will adjust the A/F ratio to compensate. Higher octane fuel does burn a bit slower than lower grade, but it's debatable as to whether that has any detrimental effects on power in the real world.

I agree that there's no point in running premium in an engine designed for regular. In fact, I always ran regular in my 2000 Z28 even though premium was recommended. Sure I suffered a bit less power at WOT, but I had plenty of power to waste :).
but 3.6l doesn't have a recommended rating which means it's optimal rating is 87 unlike your z28 which will run better with higher octane.

but 3.6l doesn't have a recommended rating which means it's optimal rating is 87 unlike your z28 which will run better with higher octane.

I agree. I was just saying I'm pretty much against using premium for almost all instances with modern cars. The only time I ever put premium into the Z28 was when I was going racing. At any other time, it was a waste of $5.

Very interesting. I had become acustomed to running premium as a general rule and never even thought to RTFM. I ran premium for the last year (since day 1). I just put 3 tanks of 87 octane through the car and my average milage went from almost 25 MPG to just over 27 MPG.

I imagine the 2005 3.6 Automatic will be 87 suggested as well, right?

I imagine the 2005 3.6 Automatic will be 87 suggested as well, right?

You are correct sir. The 3.6 manual should be as well.