What can i do to make gas mileage and maybe horse power better?

[harrycalahan]

K&n filter can only let in as much air as the exhaust will let out. Long tube headers, free flow cat(s), low flow or no muffler. Those 360's sound amazing with straight pipes after the cats. Plus all the small things that have been mentioned, tire pressure, strong ignition, correct timing, electric cooling fan... I personally have seen no difference with a k&n filter either.

 

[Sagan]

I've got a K&N in my Volvo. Only reason is that it's reusable. No change on gas mileage, but I'll be even on the next replacement (standard filter is almost 30.00).

 

[AirOpsMgr]

I guess my BMW's inline 6 paired up well with the K&N; I definitely saw a difference of +3; guess they don't work for all engines

 

[Sagan]

I guess my BMW's inline 6 paired up well with the K&N; I definitely saw a difference of +3; guess they don't work for all engines

I was wondering about that. Is yours a turbo?

 

[AirOpsMgr]

I was wondering about that. Is yours a turbo?

No, just a regular 3.0 FI, but I later upgraded the intake manifold to a 3.0SI (Same engine, just a different intake manifold) to get more HP.

I tested it over 1000K miles with the normal filter & stock manifold, then again after doing the K&N high-flow with stock manifold. Did a dyno test after upgrading both the intake & the K&N with +35 HP (but that is pretty common with this particular BMW engine according to the webz).

 

[AirOpsMgr]

Unless there is a new miracle cure out there, I'm pretty confident that your cheapest method will be intake, after that, you will spend hundreds-to-thousands on major upgrades to only yield minimal results. I'm certainly no expert on that engine set-up, but that is my experience on many others

 

[armedplinkster89]

Avoid hauling ass on the highway

 

[davidmu39]

Ok so I can tell you what NOT to do, based on personal experience from the late 70's early 80's, I don't know for sure, I tried to forget but anyway, under no circumstances should you order a "fuel pressure regulator" from the JC Whitney Catalog and install it on your fathers F100 Ford PU that has been "given" to you to drive to high school during the week while he is out of town.

Regardless of how supposedly easy it is to cut the fuel line and install this miracle fuel pressure regulator, it will leak. Should you choose to do this despite my warnings, be prepared for any ass whipping that may come your way from said Father when he returns and has to replace the fuel line on "your" truck.

 

[Tanman2003]

believe it or not an instant mpg indicator helps a lot. It reminds you to back off the throttle, and game your commute i.e give a little throttle when going downhill, and backing off when reaching the top of a hill etc.

 

[MRM]

believe it or not an instant mpg indicator helps a lot. It reminds you to back off the throttle, and game your commute i.e give a little throttle when going downhill, and backing off when reaching the top of a hill etc.

Funny how it seems those are the times people like to ride my *ss.

Small things add up. Eliminate vibration, grease wheel bearings, adjust valves, make sure you got a gap in your points, dielectric grease on plug connections, remove unneeded cargo.
I would start with oxygen sensors.