Zone chip - whats it all about?

[Wid77]

Can anyone tell me how much a zone chip would be for my 1988 325i and what are the pros and cons? Where could i get one? Will it improve power & torque but kill my fuel consumption? Will it increase wear on the engine?

I am going to service the car this weekend. If i did fit one of these chips then would i need to get the car tuned afterwards, timing etc?

Thanks

[Wid77]

Sorry but just seen the other post which i have not read thoroughly but seems to answer most of my questions. I will post there. Thanks.