fuel consumption on the nb? & gearbox ratios?

sprx3 · Postby **sprx3** » Wed Apr 25, 2007 9:42 pm

hey guys,

I cant seam to get any better then around 10L:100km with my nb, & if i drive it hard its even worse, i would have thought i should be getting 8ish from normal driving... is this nornal or should i be doing some checks?

also ive noticed the gear ratios arnt the best for hwy cruising & wanted to know what the models came out with if they are different & what the 6 speeds have in them.

cheers

StanTheMan · Postby **StanTheMan** » Wed Apr 25, 2007 9:48 pm

depends what kind of mods your car has.

excaust , CAI & so on.

My fuel consumption went up after the instalation of the CAI......because i love the sound of it. & therefore always on the gas.

Also depends how long your trip are. Loys of short trips....kiollls the fuel consumption.

davamb · Postby **davamb** » Sat Apr 28, 2007 11:44 pm

Gotta agree with ya there Sprx, sure my old Calibra used to get equal consumption when driving for economy. Why? Is there something inherently ineficient in the MX? Is the EFI a bit generous? Poor aero? Compression ratio? Hasn't got a lot of weight to pull along, I don't get it.

Alex · Postby **Alex** » Sun Apr 29, 2007 1:32 am

with my NB normally I let it warm up a bit (until the needle get's to the normal halfway point) before taking it above 4k rpm so i'm normally a slowish driver for the first 4 mins of driving before I take it up to redline :lol:

and my fuel consumption seems to be around the 10L/100km mark constantly except when i take it on long trips then I can get as low as 7.5L/100km

check your tyre pressure and air filter
also what fuel do you use?

sprx3 · Postby **sprx3** » Sun Apr 29, 2007 9:47 pm

SM wrote:with my NB normally I let it warm up a bit (until the needle get's to the normal halfway point) before taking it above 4k rpm so i'm normally a slowish driver for the first 4 mins of driving before I take it up to redline and my fuel consumption seems to be around the 10L/100km mark constantly except when i take it on long trips then I can get as low as 7.5L/100km

check your tyre pressure and air filter
also what fuel do you use?

hehehe thats funny, my easy driving is 1/4 accel & 3k ish changes :shock:

tyre pressure did make about 20km a tank difference going up form 30 to 35 psi, it has a pod which im going to look at replacing with the stock box & a k&n filter & im using std fuel, ultimate didnt give me a difference :roll:

timk · Postby **timk** » Sun Apr 29, 2007 10:43 pm

That's crazy! I get the same economy as you in the SE!

Casey · Postby **Casey** » Mon Apr 30, 2007 12:30 am

sprx3 wrote:
SM wrote:with my NB normally I let it warm up a bit (until the needle get's to the normal halfway point) before taking it above 4k rpm so i'm normally a slowish driver for the first 4 mins of driving before I take it up to redline and my fuel consumption seems to be around the 10L/100km mark constantly except when i take it on long trips then I can get as low as 7.5L/100km

check your tyre pressure and air filter
also what fuel do you use?

hehehe thats funny, my easy driving is 1/4 accel & 3k ish changes

tyre pressure did make about 20km a tank difference going up form 30 to 35 psi, it has a pod which im going to look at replacing with the stock box & a k&n filter & im using std fuel, ultimate didnt give me a difference

Did you keep the air temp sensor in about the right spot when changing to the pod filter (ie reading ambient air temperature)? If its hiding down near the exhaust manifold reading higher then normal temps the ECU might be pumping in extra fuel to "save the motor".

My SP almost never returns figures worse then 10l/100km - it is usually around 8-9l/100km in normal driving (not necessarily sparing the horses though) and even better on the freeway.

Boags · Postby **Boags** » Mon Apr 30, 2007 12:10 pm

With a mixture of highway, town and spirited hills driving I return 10L/100km at the worst. My car is running overly rich in boost at the moment too... I would regularly get 450Ks for 35L of fuel with the CAI before the turbo went in... I have a 1.6L though.

Boags

Fatty · Postby **Fatty** » Mon Apr 30, 2007 12:17 pm

maybe you need a new o2 sensor or something?

Craig · Postby **Craig** » Mon Apr 30, 2007 4:09 pm

Fatty wrote:maybe you need a new o2 sensor or something?

Gearbox neutral switch can be the culprit too, as apparently it thinks you're just revving it in neutral and hence doesn't deply the O2 sensor...or so I hear!

Boags · Postby **Boags** » Mon Apr 30, 2007 5:16 pm

Fatty wrote:maybe you need a new o2 sensor or something?

Great call! I'd be checking that first...

Boags

sprx3 · Postby **sprx3** » Mon Apr 30, 2007 7:41 pm

Craig wrote:
Fatty wrote:maybe you need a new o2 sensor or something?

Gearbox neutral switch can be the culprit too, as apparently it thinks you're just revving it in neutral and hence doesn't deply the O2 sensor...or so I hear!

ahhh now thats the kind of info im after.....

you got any more of that & where do i find it (yeh im guessing its on the box :lol:

) & how would i test it???

also guys im really after the ratios of the 5 & 6 speed boxes as im looking at going to a 6 speed in it if it has a better overdrive then the 5 speed boxes

Craig · Postby **Craig** » Tue May 01, 2007 12:42 am

From what I've heard the wirings cable tied under the car, and when a clutch is replaced the mechanics can just leave the cables dangling around, and over time the wires stress internally and break. I'm pretty sure mine needs one or the O2 sensors knackered as the fuel consumption is much worse than the NA's I used to own.

Casey · Postby **Casey** » Tue May 01, 2007 7:38 am

In earlier ECU cars the neutral switch (in parallel with the clutch switch) is only used to detect a stationary idle condition (ie car out of gear and/or clutch depressed).

Th ECU then richens the idle to make it smoother. The consequence of a failure of the neutral switch was that the idle got a bit lumpy (and your 4WS system stopped working on a MX6 turbo :roll:

)

As far a 6sp vs 5sp ratios - with the correct diffs the 1st gear and top gears are almost identical. The 6sp is just a closer spaced box. You will need to change your diff to a 3.6:1 if changing to a 6 speed or you will be grossly underdriven with the 4.1:1.

What most of us SP owners (and you too by the sounds) really want is a 3.4 or 3.3:1 diff to stretch out first gear and then bring the rpm down to about 2500rpm on the freeway - right in the middle of turbo torque country :mrgreen: