V9X FUEL CONSUMPTION

[Ern0704]

I would like to hear from other V9X drivers what their experience is like concerning fuel consumption. I have this vehicle about a year now, and am battling to get 8.4 km on a liter. This is of course not much long distance but an average of 60kms each time. According to the factory manual an average of 11kms on a liter is achievable. That's without any modifications to the vehicle yet. Mine has done 187000kms is 11 years old. Mechanically what I've done to try my utmost so far was firstly an engine flush then a throttle controller by EVC So that I can manipulate the hunting of gears by the transmission on longer uphills, although I rarely use it now. Next I upgraded the intercooler to a better and bigger one. And then the boost pipes as well and fitted an oil catch can. My driving style isn't aggressive at all. With all this power it shouldn't be so hard to get results in fuel efficiency or what am I missing. The next mechanical thing is a turbo back free flow exhaust and a remap. It's lively and driving well, but only a bit thirsty. Am I expecting to much if I day that at least 10kms on a liter would make me happy at this stage already?

 

[username_unavailabe]

Hi. In my experience (Infiniti FX30d - also a V9X, similar weight) getting anything under 12l/100km (8.3km on a liter) in the city with traffic is impossible for me, as I refuse to hold up traffic by being too gentle on the throttle. I do not push it to the floor by any means, I am still trying to be as economical as possible without holding up traffic.
When I am on country roads, driving between small towns (in Europe it is called combined fuel economy), I can get 9l/100km (11km on a liter) when I just go as I like to go (110km/h, medium to heavy on the accelerations) and the absolute best I was able to achieve on this type of mixed condition driving was 7.5l/100km (13.3km on a liter), but I had to shift in manual to keep the rpm as low as possible while accelerating. Here I have to note that when accelerating, I was pushing it to around 60-80% throttle, because overall engines tend to be the most efficient in the low rpm-s under relatively high load.
On the highway I tend to go around 140km/h and I get a very consistent 10.2l/100km (9.8km on a liter).

Looking at the numbers, if you do a lot of city driving, I think its normal - at least I hope so and there is nothing wrong with my engine either

What I did though, was getting my DPF cleaned at a specialized DPF shop. It was quite clogged and there was some sort of pipe that was completely clogged by soot, so much so, that they were not able to clean the pipe and I had to get a new one. That pipe is (I think) between the exhaust and a sensor near the engine that tells the ECU when the DPF should be burned out by the car. Doing this my fuel economy got right about 0.5l/100km better. All the values I mentioned are AFTER the DPF cleaning.

I think getting 10km on a liter should absolutely be possible when doing some driving under mixed conditions, however, almost impossible (at least for me) in the city.

Hope this helps

 

[Ern0704]

Hi. In my experience (Infiniti FX30d - also a V9X, similar weight) getting anything under 12l/100km (8.3km on a liter) in the city with traffic is impossible for me, as I refuse to hold up traffic by being too gentle on the throttle. I do not push it to the floor by any means, I am still trying to be as economical as possible without holding up traffic.
When I am on country roads, driving between small towns (in Europe it is called combined fuel economy), I can get 9l/100km (11km on a liter) when I just go as I like to go (110km/h, medium to heavy on the accelerations) and the absolute best I was able to achieve on this type of mixed condition driving was 7.5l/100km (13.3km on a liter), but I had to shift in manual to keep the rpm as low as possible while accelerating. Here I have to note that when accelerating, I was pushing it to around 60-80% throttle, because overall engines tend to be the most efficient in the low rpm-s under relatively high load.
On the highway I tend to go around 140km/h and I get a very consistent 10.2l/100km (9.8km on a liter).

Looking at the numbers, if you do a lot of city driving, I think its normal - at least I hope so and there is nothing wrong with my engine either

What I did though, was getting my DPF cleaned at a specialized DPF shop. It was quite clogged and there was some sort of pipe that was completely clogged by soot, so much so, that they were not able to clean the pipe and I had to get a new one. That pipe is (I think) between the exhaust and a sensor near the engine that tells the ECU when the DPF should be burned out by the car. Doing this my fuel economy got right about 0.5l/100km better. All the values I mentioned are AFTER the DPF cleaning.

I think getting 10km on a liter should absolutely be possible when doing some driving under mixed conditions, however, almost impossible (at least for me) in the city.

Hope this helps

Thank you for the reply. My sorry of driving involves shorter trips or what we would call shorter trips here in south africa of about 34 to 70km at a time. Long trips are anything from 300km and above for me. On those longer trips my best figure that I got was 9.4 km per liter that was before I gave it a free flow exhaust of 76 mm from right behind the turbo to the back end with one enormous round free flow resonator. As well as a safe remap, and stainless steel hot and cold pipes as well as an oil catch can. It sounds great doesn't smoke at all and goes like crazy. It's just the fuel economy that still has me baffled because I don't tend to drive aggressive and are very cautious of to long or even to short a stay in a gear. I would say I'm trying my utmost in being a good driver not straining the engine or transmission in any way and only on demand when passing other vehicles do I enjoy the power I have to my disposaleven though I don't floor the pedal ever, and then I return to being economical.

 

[username_unavailabe]

Thank you for the reply. My sorry of driving involves shorter trips or what we would call shorter trips here in south africa of about 34 to 70km at a time. Long trips are anything from 300km and above for me. On those longer trips my best figure that I got was 9.4 km per liter that was before I gave it a free flow exhaust of 76 mm from right behind the turbo to the back end with one enormous round free flow resonator. As well as a safe remap, and stainless steel hot and cold pipes as well as an oil catch can. It sounds great doesn't smoke at all and goes like crazy. It's just the fuel economy that still has me baffled because I don't tend to drive aggressive and are very cautious of to long or even to short a stay in a gear. I would say I'm trying my utmost in being a good driver not straining the engine or transmission in any way and only on demand when passing other vehicles do I enjoy the power I have to my disposaleven though I don't floor the pedal ever, and then I return to being economical.

Can I ask what your fuel economy is at a fixed speed, set up through cruise control on a flat road? Lets say you went a consistent 100km/h with no incline or decline on the road. Do you know what the fuel economy is at that time?
If you know it at any specific speed, I can test it in a couple days and let you know.