So I was talking with a coworker of mine who in a previous life has been a auto, truck and semi mechanic, specifically focusing on engine life etc. and the topic of gas mileage came up...I am sure that given gas prices these days, it's like talking about the weather.

Anyways, I mentioned to him that my only mod...ztube & jwt pop charger and that I also have K&N in my wife QX. Anyways, he said those are crap and hurt the engine. After I calmed down from my "screw you" speech, he calmly explained and it made sense to me.

He referred me to a site "Bob the Oil Guy" as a point for me to research and said he current has 5 vehicles in his family (Infiniti, Nissan, Lexus, Ford, Chrysler) at home which he maintains himself. He, up to a about 2 years ago, swore by Cold Air Intakes, etc. but he happen to send his engine oil in for analysis on all 5 vehicles. The results showed high amounts of silicon, iron, potassium, chromium, copper, etc. i.e. metals that should only exist in extremely small amounts, if at all.

Over the course of a year, he started making small changes and resending samples. Changes included...using better gasoline (shell, bp, mobil vs the generic wholesalers), utilizing Mobil1 synthetic and then Mobil 1 Extended Performance, and finally removal of air filter. While the gasoline and engine oil made difference, going back to OEM paper filters and then switching to High End filters like Amsoil and Bladwin, completely changed the oil test results and virtually eliminated the contaminants.

Now granted that environment has to do a lot with it, e.g. in WI we could end up getting higher concentrations of sodium or potassium because of salting of the roads. Each car belongs to a different family member who has different routes and driving styles and the story ended up the same way. And silicon is the worst enemy of engine life.

So today he is running Mobil 1 Synthetic extended mileage, with regular changes in paper air filters, and Shell 89 and is way below the average on contaminants, and is able to get 13500 miles before an oil & air filter change. The oil test results tell him he can go to 15k miles, but he is playing it a little safe. 1 car has 180,000 miles and the engine still purrs like a kitten.

So long story short...I have just sent oils samples from both my G35 and wife's QX for analysis. both run Mobil 1 synthetic, changed every 5500 miles and both have had a JWT and K&N filter since week 1. G has ~10k miles and QX has ~32k miles. We shall see what comes back.

So has anyone ever had their oil tested, does engine life and health warrant getting rid of cold air intakes? This guy spend over $600 in testing oils to prove it to himself, could he be right?

 

He "could" be right,.. but pigs could fly,.. someday, maybe.
But in seriousness it is possible that in the quest for better breathing performance a lot of aftermarket filters sacrifice some degree of filtration and in the process are letting small amounts of silicates and other air born particles though.
I have really had no experience with oil testing or filtration design but it seems to me that this would be a very large over site (on the filter companies behalf) if it was completely true though.
I have however seen somewhere i think on here some time ago where someone had a comparison of several filters for their filtration and flow rate characteristics that was very interesting but I cant seem to find it and I somehow doubt that most aftermarket filters are secret death pieces for our engines.

P.S. If it is indeed true, most people these days dont own their cars for 180,000 + miles anyway so I imagine to most people the performance gains would be worth it, just guessing though.

 

I would think most engines today, the VQ specifically is more than capable of 200k miles even with a oil'd air filter. this isnt the first time though that I've heard of this argument. The reason these filters flow more air is because they simply just allow more air through, which means you will get more dust particles obviously. I think if you take the time to look through a freshly cleaned oil'd filter before you re-oil'd it you would notice its fairly transparent.

Keep us updated with your oil survey.