cold air intake

The factory one with a Bmc or K&N filter.

heylinTTnz said:

The factory one with a Bmc or K&N filter.

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thanks. should i use the factory air box or buy a heathield so it is open?

Save your money. The standard filter is good for 600 bhp.

audi a5 3.0 tdi said:

thanks. should i use the factory air box or buy a heathield so it is open?

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Factory air box with a drop in filter, good enough for RS5 so should be fine for a 3.0 tdi, unless you are going for stage 2+ tuning and supporting mods for big HP, the factory intake is fine.