I'm getting about 300kms per tank (about 50L) so 17 L/km... thats a heck of a lot worse than the obese SUVs of today lol So a while back I had the zed professionally dyno tuned. I can't remember what its prior mileage was like. I never really took notice. Currently its set up with -AT to MT conversion -stock AT turbos -stock injectors -low boost is 10psi high boost at 15 always use 98 fuel -EBC and nistune -3" zorst + high flow cats and are still functional -larger pod style intercoolers -lightweight front pulley, chrome molly flywheel, ally tail shaft -deleted all the crap under the plenum -fat ally radiator, new water pump, new lifters, timing belt etc etc etc -wheels have been aligned, brakes aren't dragging, wheel rotate freely, wheel bearings have no play and aren't crunchy / roll smooth After I got it back from the tunas, I noticed it now makes black carbon deposits on the rear bar (obviously they've tuned it to be fat) Also just did a compression test 170~165 psi all around. Spark plugs look very clean... almost as if it was running lean. So do you guys get around the same fuel economy? Or is this a sign that something's broken? Cheers guys
Our tanks are 70L in size. Might get 65L or so in at each filling. Most TTs would be lucky to get around 500km out of a tank for a mix of highway and city. Anyways, that's around 13-14L / 100kms on average so yours isn't terrible assuming mainly city drving (start stop?)
Sounds like it's running super rich. Oxygen sensors have probably been disabled too (no closed loop).
You can't really tune for economy or performance as cruise/idle (where you want economy) and WOT (where you want performance) are different areas of the maps.
Ok, so it seems my tank gauge is out of whack. When the needle hits empty, I can only fill in 55L at most... so that explains my lack of range... Though the consumption per distance is still pretty high. Or is this fairly normal? It was most likely tuned for power, temp control/quenching, knock control etc. I haven't been fouling plugs so its not that bad. Though I think one side is burning more fuel than the other bank. Result of tuning on dirty injectors maybe?
There's no such thing as tuning for econony or power. A good tune will have both. As magicmike said its a completely different part of the map.
Ok I will correct my self You can eater: De-Tune the engine to lower emissions and operate smoothly over a wider RPM range. (economy) Or Tune it to increase power output (performance)
Not uncommon but can be improved, have a chat to the tuner and see how he'd feel about improving the cruising and low load cells and maybe whether he thinks your O2s were ok. Expect you cats to be toast in a few thousand ks if you leave it as-is.
do you have your dyno graphs showing the air fuel ratios? mines running 740 cc injectors and getting around 450 to a tank
Fuel tank size The fuel tank is indeed 72L, but I don't agree with MagicMike. The point where the fuel light comes on is 55L. This is well known.
hang on... when you guys say you get 450kms to a tank... is that using 55L until the light comes on or until the fuel pump runs dry? So with 17L in reserve and with my current consumption, should I expect to drive another 100kms (less the little bit the pump can't pick up)? This sounds a little excessive :/ Gotta drive back to sydney from newcastle now... I have 10L in a jerry can... so I'm tempted to see how far it goes... or I'm just assuming I'm going to cook my fuel pump :/
lol, no offence, but it always amuses me people trying to make comparisons on subjective data. Bit like comparing dyno figures lol. The only way to compare fuel mileage is by writing the odometer km values at each fuel stop, recording the number of litres, and then doing a calculation. And TBH even this is subject to the accuracy of the fuel bowser used (of which I'm certain there are quite a few in Sydney overcharging!). Not to mention how, where and at what speeds it's driven. The fuel light may be set to come on at 55lts from factory, but this may actually be 58 lts on one car, 53 on another, 62 on another. Only way to know this would be to completely drain the tank, then fill it full, then immediately the fuel light comes on refill it. And don't forget to take into account the angle of the vehicle off horizontal.
What is this fuel light you speak of? Have owned a few Zeds in the last 4 years and never once seen a fuel light and have been down below the E on several occasions... perhaps its easy to miss or often faulty? Aside: I use this (Android App) to track my fuel usage ... does several cars and can also track expenses My Cars I generally get 8 to 9 km/l
02 sensors control fuel air mix Check to see if your 02 sensors are working. High and low switching cycle voltages every few seconds and the heater coil in the 02 sensor are still working. If your 02 sensors are faulty you will not be able to get good fuel ecom.:zlove: