Extractors V's fuel economy / power

Hi Guys,
I have a 1993 Patrol with a 4.2 petrol engine, it has done 200,000km.
Would putting a set of extractors / headers on the exhaust system help with fuel economy and power?
Or is it best to change the whole exhaust system?

Thanks.

Neil.

Every little bit helps, but if you're going through the trouble of fitting extractors, you're better off going the whole system as the stock form is very restrictive.

X2 as above. If finances permit do the whole system, I would also get a tune done after as well which will also help.

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Headers will help as long as you avoid the right foot as it the sound will be better and most of us have a tendency to give it a squirt due to the nicer note.
Make sure you pick a set of headers for the type of driving you mostly do.
For more low-mid driving a different design to full rpm racing will be required. Don't be tempted to go the bigger is better ideal as it won't be. Have a chat to a couple of exhaust shops and see what the common recommendation is. Explain to them what you want and let them recommend a system to suit, after all it is what they do for a living, they will sell you anything if you tell them that you want size so and so.

I would be thinking a 2 - 2 1/2 system with a decent free flow muffler to suit the desired volume, just allow for drone when cruising and pick an appropriate muffler setup to avoid it.
Probably something around 1 1/4 - 1 1/2 primary pipe size should be about right.
Use that as a guide only as I am not an exhaust expert by a long shot

i had pacemaker extractors with a free flowing 2.5" system on my tb42e before i went turbo, the extractors and exaust definetly helped with power and economy my best figures were 13l per 100km on a freeway run between werribee and sale while fully loaded. around town expect about 20l per 100km. you definetly need to fit a decent cat back to go with the extractors as the std system is quite small and restrictive.

I got a Turbo upgrade on my 2006 Y61 TB42 from United Fuel injection in Perth WA and they insisted i upgrade my exhaust to 3" and believe me the combination was absolutely amazing, i did change the exhaust to 3" before doing the Turbo upgrade and that alone made an impressive change...size does matter lol