I'm not sure if youre serious or not? Standard conventional oil should be changed at 3k, but usually there's still plenty of life left if you were to get very scientific. Synthetic is made to go to 5k.

And why does Mobile1 suck? And if so why did 71, 000 go by for you to form that opinion?

Ive read that Royal Purple is bad for the VQ. Ive heard that conventional vs synthetic oil is better/worse. I don't know what this is based on besides opinions?

 

UPDATE: 5/2/14 I took my car to the dealer and they replaced the passenger side cat for free under the 8 year 80k mile federal regulation/law/whatever. I have not noticed the noise since.

 

I thiught you were doing tjis 6 months ago. Also therevare much better oils than mibil 1' amsoil and royal purple to name a few.

 

I was going to.....there's this curse in Iowa called "winter" or as I called tbis one: The Never Ending Story.

I had Royal Purple in for about 40k miles and one of my buddies said it wasn't good for VQs for whatever reason. It's all hearsay imo but Mobil 1 hasn't essploded my engine so it's all good in my hood.