Dealer Oil Change

[MRSocal]

After an oil change at the dealer at 6,000 miles, I realized that something isn't right. The acceleration was unusually sluggish.
Two days later, I decided to change the oil again in my garage. The drained oil was not dirty but it was dark, much darker than fresh full synthetic oil.
I went for a drive after changing the oil and my Z was normal again like night and day with major increase in acceleration response. I was relieved!
Did the dealer accidentally put non synthetic oil or heavier weight oil? What could have happened if I didnt realize that something was wrong with my Z and kept driving it with the dealer oil?
Your thoughts please.

 

[dohanhoney]

I noticed a sudden drop in engine performance shortly after the oil change at the dealership. Curious, I checked both air filters and found a leaf lodged in one of them. Removing the leaf fixed the sluggishness. I suspect the technician checked the air filters and, while putting it back, a leaf got stuck right by the sensors. I hope this helps.

 

[Zplz]

After an oil change at the dealer at 6,000 miles, I realized that something isn't right. The acceleration was unusually sluggish.
Two days later, I decided to change the oil again in my garage. The drained oil was not dirty but it was dark, much darker than fresh full synthetic oil.
I went for a drive after changing the oil and my Z was normal again like night and day with major increase in acceleration response. I was relieved!
Did the dealer accidentally put non synthetic oil or heavier weight oil? What could have happened if I didnt realize that something was wrong with my Z and kept driving it with the dealer oil?
Your thoughts please.

Didn't you get a statement of your dealer service? They always give me a printed statement, with the service performed and the type of oil used.

 

[Jim Calombaris]

So, if you didn't know, after draining your oil on a stock oil pan, it does not fully drain leaving about 3/4 of a quart of old oil inside the oil pan! Not sure why they didint engineer the stock oil pan to drain fully! This is why many of us replace the stock plastic oil pan to an aluminum pan that does drain the oil like it should! As far as your performance drop, not sure about that but it should have nothing to do with the oil change!

 

[Dying Star]

So, if you didn't know, after draining your oil on a stock oil pan, it does not fully drain leaving about 3/4 of a quart of old oil inside the oil pan! Not sure why they didint engineer the stock oil pan to drain fully! This is why many of us replace the stock plastic oil pan to an aluminum pan that does drain the oil like it should! As far as your performance drop, not sure about that but it should have nothing to do with the oil change!

I noticed this with the dealeship I bought it from, but I went to another dealer because I had a falling out with the first one about lying about adds ons and sales, and the other dealership that gave me a service coupon, legit actually tuned it and hooked it up, my transmission is incredibly smooth and responsive with no rev overhang when shifting. Dude its a completely different z And feels faster. Maybe it was the transmission change for the 10k service, but i know they did something!

 

[trackratZ]

Dealer owns and is responsible for that drastic performance drop. They must provide you with the written invoice and oil/filter used. Very baffling but scary thought! Did they use a much heavier weight oil? Go back to them and let us know. Some dealers here in warm CA have used 5W30 and approved it, but I bet no heavier weights should be used. That huge change in performance can't be attributed to just the OEM oil pan leaving a little bit of the old oil in.

 

[Tranzor Z]

KrackaC8 is my dealership

 

[Who.Am.Eye.2716]

Never heard of oil causing performance issues. Could it have been heavier oil, maybe

0w20 is thinner and less resistance. It is standard for the Z. They could have used 5w30

I use 5w30 after my 1200 mile break in. Mines a manual. Its about dumping the clutch and stomping on the gas pedal to go fast

 

[takemorepills]

This makes no damn sense.

The dealership accidentally knocked the charge pipe off my previous turbo car during service, oddly it drove fine without CEL, just had no juice...... I was kinda expecting OP to say they found a charge pipe dismounted, but saying that a second oil change corrected the issue, WTF?! Interesting.....

 

[MRSocal]

Dealer owns and is responsible for that drastic performance drop. They must provide you with the written invoice and oil/filter used. Very baffling but scary thought! Did they use a much heavier weight oil? Go back to them and let us know. Some dealers here in warm CA have used 5W30 and approved it, but I bet no heavier weights should be used. That huge change in performance can't be attributed to just the OEM oil pan leaving a little bit of the old oil in.

I think the dealer used either a heavier oil or a non-synthetic oil. This dealership is reputable. They serviced my old Z cars for years. I've known the service advisor for long time and I'll go back to talk to him. I'm just thrilled that my Z now performs like it should.
I drove it again this morning and the acceleration and engine purring was awesome.

 

[Zplz]

I think the dealer used either a heavier oil or a non-synthetic oil. This dealership is reputable. They serviced my old Z cars for years. I've known the service advisor for long time and I'll go back to talk to him. I'm just thrilled that my Z now performs like it should.
I drove it again this morning and the acceleration and engine purring was awesome.

The service department should have a record of the service, with the oil they used, even if you don't have a copy, which is puzzling to me. Every dealership service I've used over the years has given me a copy of the service the vehicle received and most usually send you an email copy of it, too. I just checked my latest oil change from my Nissan servicing and the oil used is listed on it. This shouldn't be a great mystery.

 

[trackratZ]

I think the dealer used either a heavier oil or a non-synthetic oil. This dealership is reputable. They serviced my old Z cars for years. I've known the service advisor for long time and I'll go back to talk to him. I'm just thrilled that my Z now performs like it should.
I drove it again this morning and the acceleration and engine purring was awesome.

I think they owe you free next oil change or a refund, since you had to drain and re-fill on your own dime. Go for that when revisiting them, esp since you know them well.