Air filters?
 

When are we supposed to replace these? I had heard 15k/18k from the service advisor i believe, but I don't see it in the infiniti maintenance manual until 30k / 24 months.

Also, for 15k it is saying "replace brake fluid" along with the cabin air filter (understandable)..but can't say I've heard of the brake fluid being replaced so soon?

Also has anyone had success using the K&N high flow filters? Or should i just go to a CAI setup and not bother with those? Looking for some opinions..

Go with what the owners manual says. Don't listen to the dealer. Upsell is their specialty. Brake fluid at 15k is nuts.

Stick with paper type filters and change them as required by Infiniti, or more often depending on your driving conditions. Just check them every 6 to 12 months to see how dirty they are. It takes 12 seconds to check each one. The stock intake system is very well designed and provides great airflow. If you are just looking to do a sound mod then go for it I suppose, just don't expect noticeable performance gains.

You'll probably be able to find several threads on CAI and K&N and find multiple opinions. I have a takeda cai and like the look of it. You'll notice a change in sound of the engine right away. Resetting the ECU or getting a tune through uprev or hypertech may give you a more noticeable difference in performance gains.

I totally agree with canucklehead, brake fluid change at 15k is throwing money out the window.
Concerning air filters, don't make the mistake I did and replace the stock filters with K&N filters. I thought I would buy a pair because they can be cleaned and re-used and are probably useable for many years. They are also advertised to give you a couple extra horse power. After I installed them, I decided to check out what others had to say about their performance. They cost $60 each plus the necessary cleaning solvent and re-oiler which comes to about $135 total. If you don't mind spending that much on filters that's OK, but the bad news is --these filters do NOT filter as well as the factory filter. You get a little more air flow thru the K&N, but by doing so, larger particles of dirt will get through the filter. I have also heard that if you over oil the filter, it has been known to do damage to the mass airflow sensors. I could tell absolutely no difference in sound or performance with the K&N's. I eventually took mine out, sold them on ebay, and re-installed the factory filters. In my opinion, K&N filters are a waste of good money.

Totally agree about the K&Ns. Just hold one up to the sunlight and you'll see why they flow better. I figure if I can see holes with light coming thru then dirt will also get thru.

And when you're ready for filters hit up RockAuto, about 1/2 price compared to the dealer. Get 4-6 oil filters and a couple pairs of air filters and you're good for a couple years. The WIX air filters are great IME.
2009 INFINITI G37 Air Filter
More Information for WIX 49362

If you have NAPA Parts local to you..they sell their Napa Premium filters which are Wix filters. As far as intervals it all depends on the area you're driving. If there's a lot of construction zones around the area I'd change it more often.

If you track your car, changing brake fluid frequently is definitely not nuts. A little bit of absorbed moisture does a good job of creating soft or almost useless brakes when things really heat up. For normal street driving, time is probably more important than mileage.

Look at them

http://i209.photobucket.com/albums/b...ilter_3619.jpg

This photo was taken after 10k miles on my 06 G35

http://i209.photobucket.com/albums/b...10800miles.jpg

After seeing that I generally change Air Filters after 8k miles upon inspection

Telcoman

Telcoman

Thanks for the link..gotta love Rock Auto.

I looked at them today and I would say they're fairly dirty, so I'm going to do the filters soon with the next oil change. I drive a lot of highway so there were some bugs and crap from the wind in there.

Damn, are you using your G as a sandbuggie rescue vehicle? Mine look half that dirty at 15k.

Air in New Jersey is dirty

Air filters become more efficient as they trap more dirt before reaching the limit where they need to be replaced. New filters let more dirt in the engine than dirty ones, it would actually hurt the engine if changed out too often.

00Max00---I absolutely do not understand your post. What you say may be true, however, can you site any study or test that verifies your statement? I could understand that a dirty filter will reduce air flow, but a little bit dirty filter is better than a brand new filter? Me thinks that the only thing that changing a filter too often would hurt would be your wallet.!!!!!!!

^^^ Well, I try to explain a bit, but you can google it for better answers.

Air filtration is a balanced act which means with given filter material and size, the more air flow you get, the more dust it allows to pass. You get maximum air flow when it is new. As the filter gets dirty, bigger holes are plugged with dirt and allow only smaller dust through, hence enhanced efficiency. The side effect is air flow gets more restricted, as the process goes on, to a point where air flow is too restricted which affects normal engine functions. Infiniti calls for 30K/24 months filter replacement, you are perfectly fine following that schedule. It does you no good to change it often. It is not about money.