Do K&N filters really improve bhp on discovery tdi?

I have a 300 tdi disco and want to improve the bhp cheaply
I know the best way is an intercooler but too expensive at mo!
Do the K&N filters really work for discos??
Cheers

hardly noticeable.

wouldnt bother wasting your cash.

jim

No, you would never tell the difference, If you need a new filter anyway They may be worth the extra though.

Is there another cheap way to increase bhp?

Fitting a K&N filter won't improve BHP but you should get a small but noticeable improvement in performance. My son did (on his 300 TDi Range Rover) and I did on my TD5 Disco. Whether it's worth the additional cost is debatable. You can also add a friction reducer to the engine (we both use Activ8 and, again, have noticed improvements. Another cheap way is to disconnect your viscus fan. Under probably 95% of operating conditions this is not necessary and is certainly using up precious bhp.

What is the viscous fan ??

Engine cooling fan, mounted to a viscous coupling behind your radiator (not to be confused by electric fans fitted in front of the radiator on vehicles fitted with air conditioning). This is constantly driven thereby providing cooling even when it is not necessary.

I had a look at the TD5 downpipe and there is a small difference in size between the TD5 and the TDI. So I am considering doing the same exhaust that are on the TD5 on my 300tdi

A 300 TDI will take slightly more fuel even with a STD intercooler giving more power.