For petrol I get around 15-20 city driving and around 10L/100 on the freeway. Thats with everything running sweet, I have no open loop portion of my map and don't run conventional O2's, but my maps are spot on, unfortunately coming on and off boost in traffic just fks over your fuel consumption, it's the way it is.
When going to/from Goulbourn for Nissan Nats I was able to get 600km just before the fuel light lit up, so I'm guessing maybe 700km/tank in my TT. Usually driving round town with a few spirited bursts gets me 500 when my empty fuel light comes up. IMO, new O2's (cost $200), clean air filter and a tuned ecu (I run nistune) are well worth it just because of the fuel savings youll pick up! So thats about 10L/100km highway and about 14L/100km around town.
there are so many causes for fuel consumption issues and they have been discussed previously. You mentioned the spark plugs are of a light brown colour, consistent with a slightly lean mixture. The VG30DE (TT included) is a very unusual engine in regards to the chamber?s combustion, I have been finding out heaps about it as I try to get my car pass the emission requirements for rego. Like for example, it is inclined to run with a lot of excess oxygen after the combustion cycle. Of interest, there is very little NOx generated, and it is inclined to allow a little HC to pass through regardless of the level of CO. Which leads me to think the EGR valve was to help address the HC generation more so than the NOx. What does that all mean,? I could go into combustion theory for you, but it would take for ever. Needless to say I have my car down to 6.5ltrs/100km, on the combine cycle test. And yes I can prove it too, with certified tests (as I have too). Understanding that my car is a lot lighter than a Zed, it certainly would not translate to greater than 10lts/100km on a well tune engine. As such you should be getting that mark for a standard engine. As an example you may be indicating a lean condition by you sparkplugs, but what if this is because you have a lean misfire. Or a low compression firing, because your timing is too advanced. Or, the fuel is not vaporising properly because your injectors are fouled, or the fuel pump is worn, or the fuel filter blocked. Does it hesitate or cough, hard to start when cold, etc? I suggest that you can take two paths. The first logical path I?ll suggest is that you take it to some one that has a five gas analyser, not just a check of the air fuel ratio. Have them check record the gases at idle, 2000RPM and 3000RPM. Don?t worry about load, in neutral is fine. I can analysis the readings and let you know if there is a break down in the efficiency of the combustion, and where it could be coming from. The Second method is what I call ?shot gun? approach. Where you start changing out stuff until you find it, just by trying to target what the area might be. I touched on this earlier change the fuel filter, check the timing (assuming that you are running the standard ECU), do and injector clean, check the ECU codes (o2 sensors, etc). And, keep going.
This is worth a good look, you have uneven compression from one side to another (regardless of other discrepancies in results) which as a few people have suggested could indicate the timing belt a tooth out somewhere. When I got my first Zed it had the timing belt a tooth out and the timing massively advanced at the CAS to try to rectify this, caused all sorts of weird issues. Check the positioning bolt on the CAS, should be at 15 degrees.
I wouldn't worry too much about Hidd's consumption, he probably has bullet holes in his fuel tank. After getting new 02's, a new coolant temperature sensor and plug, bypassing my faulty detonation sensor and adjusting my idle, I get less than 10L per 100 on the freeway used to be 16! Find eBay seller StencilCaps. Cheapest 02 sensors in Australia at $78 delivered. 15 month warranty too.
no probably, i do... hell im surprised when you just came to mine your car wasnt filled with them also!
+1 for StencilCaps, got some the other month, easy to fit up, quick delivery and theyre still working perfectly fine
60 litres of fuel gets me city with a few shorts squirts of boost 450 klm 13.3/100klms country steady state driving gets me 650 klms 9.2/100klms flat out track sprinting gets me 110 klm 54.6/100klms My fuel pressure reg is set 5 psi higher or I would get a fair bit better economy. It was done to put a bit more fuel in to combat detonation.
Fill up your tank until it clicks off once. Reset your trip meter and drive for as long as you want. When you refill do the same as before.....fill until the first click off. Now look how many liters you just put in the tank, and look at the trip meter to see the number of kms you traveled. Number of kms divided by number of liters used will give you an accurate measurement of your fuel economy.
This is how I measured my economy. Filled up near home on the freeway, drove for 202km and filled up at Gympie. The car took exactly 16 litres to fill to the same level.. Painful as it was, I drove at speeds as close to 90 as possible with the cruise control the whole journey, since a good part of that drive has a 90 limit. The only difference being, I filled right to the very top lip of the filler pipe (1 more drip = over flow), this way could be assured of the exact level. So you may chuckle, but the cars are capable of it. The current Z has the same stellar fuel economy, but worst case for me because it has gobs of HP, my last 1/4 tank around town went in 65km When I drive to and from my property near Gympie 440km round trip, I have about 1/3 tank on the gauge to the ---EMPTY--- and then a further 14 litres once the fuel light comes on. The ECUtalk gauge also shows the real time economy of between 8 and 9 L/100K at most times. Most of the time I get 400-450 around town, but that is exclusively due to driving style. I didn't buy the car to drive like dad.
Well, I disconnected the o2 sensors which made it idle/run erratically, as was suggested so, they must be working Economy is much better, 120kms on 3/4 mark, so prolly even better once tank is refilled as it goes down quicker at the first half. That's half h'way/half traffic btw........
Yeah im having the same problem in my NA. Im getting about 16-18/100 but a lot of my driving is short distance and quite a bit of stop and go. I ran a scan on mine and it did give me any error codes so im not sure what it is. If its not showing error codes is there still a chance that my sensors could still be screwed?
Very easily. You record the speedo reading every time you fill up and you always fill up to the top and record how much fuel went in. Over time those numbers will give you a very accurate picture of your fuel consumption. However, if you have non standard rear wheels, that will introduce errors into the calculation that you will have to correct. For example Stock 16" wheels with 225 x 50 - no adjustment 17" wheels with 235 x 40 tyres - subtract 1.9% 18" wheels with 255 x 40 tyres - add 4.7% and lots of other numbers
I have 1000cm injectors, rich tune @ about 11:1 on WOT and I get 400+ every time, mix of built up area driving and mountain runs. + 5% extra distance for 18's - I never considered this in my consumption before, thanks Barry
Yes definitely. Many of the components that throw error codes when they fail can also display no error when they are just faulty. Many error codes are only evoked when there is a complete loss of signal from a component, were as the component may send inaccurate signals for a long time without triggering an error code.
I drove from Sunbury to Bairnsdale on half a tank, a 4 hour drive with mostly straight roads with minimal braking & occasional boosting. If that gives any indication on economy, I was fairly content.
And then you feed the numbers in a spreadsheet and create a graph. This is the fuel consumption from Silver since I bought it 2.5 years ago. Stock TT auto Mainly Sydney driving on major roads to/from work in the city. Some traffic jams, some motorway driving. The 20l/100k are when det sensor resistor has fallen out and car is in safety mode. The dip to under 10l/100k is last years Easter trip to Armidale
And here is the fuel consumption for the convertible. NA, manual and more mixed driving, but still mostly city traffic
