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Hi fellow TDIers.

I am new to Hypermiling and I am looking to change/upgrade my air filter and was looking for any direction any TDI drivers could add.

TIA.
Kevin

Hi Kevin, it is best to stick with the OEM (Mann) filter. They have no problem flowing way more air than what the engine needs. The MAF in these cars doesn't always get along with the extra dirt and oil that high-flow filters let in so I don't recommend high flow-filters to anybody. Check out tdiparts (http://www.tdiparts.com/catalog/)or worldimpex (http://www.worldimpex.com/index.html) if there is no place in your area to get one. Your car is an A4 chassis with the ALH engine if the websites ask for that information.

stock is usually best w/ VW's

Agree. Stock for that car. Oil-based filters like K+N will actually damage the MAF sensor not only because of dirt, but because of the oil on them as well. Once any particles get on the MAF, it shorts out.

Also, the air intake on that car is non-restrictive. It doesn't use a butterfly throttle body like a gas car, just a big wide open air intake. The only things that restrict air flow are the intake valves.

If you want more power/FE, you could tune your injection pump (phaser) with VAG-com software (and laptop) - see tdiclub.com. You could also 'chip' the car. But don't mess with the filter!

Agree. Stock for that car. Oil-based filters like K+N will actually damage the MAF sensor not only because of dirt, but because of the oil on them as well. Once any particles get on the MAF, it shorts out.

Also, the air intake on that car is non-restrictive. It doesn't use a butterfly throttle body like a gas car, just a big wide open air intake. The only things that restrict air flow are the intake valves.



I beg to differ. TDI's do not have variable lift valves, if that is what you mean. The cylinder is ALWAYS full of air, either to atmospheric or above pressure.

The generated power is dependant on the amount of fuel injected, which means that this fuel always burn in an oxygen rich athmosphere, which is why NOx emissions are higher for a TDI than a gas engine.

I beg to differ. TDI's do not have variable lift valves, if that is what you mean.

Not what I meant... Just stating that the only restriction the air intake has is the valve itself (open/closed). The rest of the intake tract is wide open.

Believe me, I've been in those engines enough to know they aren't vvt.

The best air filter in the world. No oil and the latest in technology.

http://www.amsoil.com/storefront/eaa.aspx

I'll agree with most of the other posters... stick with the stock filter setup. It takes in and cleans more than enough air for your engine. Also think about the location of the air intake before changing it. It's done that way for a reason.

Also, while you're in there, clean out the snow screen. It's part of the air intake system - the snorkle before the air filter. There's a tube with mesh at one end to block large particles from getting to the air filter. I cleaned out my GF's after 100k miles, and there were sticks, leaves, cig butts and gunk wads sitting in there. Not so nice.

Or...you can just remove it or cut it out like I did, then attach some window screen to the intake at the front of the car. Lots easier to clean.

Yeah, it is QUITE a pain in the knuckles to get that bad-boy out!