X3 3.0 SI 2007 - INCREASED CONSUMPTION

[Mentat]

Originally Posted by YANNIS

could you pls explain why not to use 98octane???thanks

My english is not very good, but I'll try.
X3, like many other cars are constructed to work even with 91 octane (see US fuel).
95 octane is optimum.

98 octane has a highter burn rate, and the car computer "learns" new figures.
In my Subaru Outback 3l I had big consumptions with 98 and 100+ octane fuel.
After a visit to the shop, I found that it was a common problem for Subaru users and generally for non-turbo petrol engines.
They reset the engine computer to the original values and asked me to use ONLY 95 octane !
For Subaru Forester 2.5 XT (TURBO) they are recommending 98.

I saw a big change (good) after that.

[Ajogu]

US fuel octane is NOT the same as Euro fuel octane.
Read this thread guys. JCL gives a good explaination here.
http://www.xoutpost.com/lounge/4441-w...ghlight=octane

[Scottie]

Since owning my 3.0si X3 I have only ever put in 99 Octane Petrol (Tesco).

V Power is 98 octane and Ultimate is 97 Octane over here in the UK.

Around town I get average 21mpg (imperial mpg) and on the Motorways 26mpg (imperial). Car has only cover a 1000 miles.

[bmw5]

My 2,5si was getting 14,2 l/100 kms before resetting the average consumption and now it has 18,5 Can it be correct?

[AzNMpower32]

Originally Posted by bmw5

My 2,5si was getting 14,2 l/100 kms before resetting the average consumption and now it has 18,5 Can it be correct?

Depends on what kind of driving you've been doing since the reset. My X3 2.5i automatic gets about the same 18,5 l/100km doing only urban driving. Usually though, I have a good dose of extra-urban driving which bumps the average. I'm down to about 10,2 l/100km on average.

[bmw5]

Yes,it is urban consumption but 18,5 is a lot.The Touareg V6 has the same consumption.Nevertheless, BMW says 12.8, 7.3, 9.3.

[AzNMpower32]

My mistake on my previous post. I didn't quite do the conversion correctly. I meant 13 l/100km, or about 18,5 miles to the US gallon for urban driving.

18,5 l/100km is quite high for urban driving; it's about what the X5 4.8i drivers are getting actually! Answer the following:

1. How are ambient temperatures in the area? Are you running the air-conditioning freqently in urban driving?

2. What grade fuel are you using? Is it a high-quality fuel?

3. Are your tyre pressures checked and set correctly? The recommended pressures are 220 kPa minimum front & rear. Check pressure when cold/before your first drive of the day.

5.Do you have any additional weight in the trunk that you needlessly carry around?

If all these conditions are met properly, then you may have an issue with the vehicle ltself.

[bmw5]

The temperature is around 8 Celcious and i always use the air condition.
In Greece the high quality fuel is the 100 octane gas.I use the 95.
Actually,i have never checked the tires since i depend on the sensors.I will tomorrow.
No additional weight in trunk.

When i reseted the consumption i was getting instant readings.I was amazed by the fact that at low revs(1,2 to 2000 rpms) and at idle it was showing 12 l/100,20 l/100kms.At least at idle,being used to the Touareg the instant consumption should be 1,2 l/100 at neutral or 1,5 l/100 kms in drive.

[AzNMpower32]

Well, the instant fuel consumption reading while idling is never accurate because when you are not moving, you are infinitely consuming fuel. The instant fuel consumption simply shows 30l/100km as a base reading when you are stopped.

To view instant consumption, you may dive into the hidden on-board computer functions. Start with the vehicle off, key out.

1. With your left hand, hold the S/R button in the instrument panel, while turning the key to position 1. The OBC will read "test __"

2. At this point, keep pushing the S/R button until you reach "19._". Then, it will alternate between on and off. When it shows off, push the S/R button until it shows "4._"

3. After a second or so, it should show "4.0 _ _ _ _ _ ". You may start the vehicle at this point. Numbers should show up in the blanks as you accelerate. This is instant fuel consumption. "136" translates to 13.6 l/100km. Note that with a cold engine, fuel consumption is substantially higher.

4. Under light acceleration, fuel consumption should spike at the beginning, around 50-80 l/100km, and it should steadily decrease. At highway speeds on a flat gradient, it should be between 6-11 l/100km cruising at 100km/h.

5. When you coast and let off the throttle at anything above 50km/h, the consumption should drop to 0 (and the thing should read "000"). This applies to manual transmission vehicles and '07+ X3s with the newer automatic transmission with earlier torque converter lock up.

Here's mine under light acceleration (I apologise in advance for the less-than-stellar quality):

[Ajogu]

Originally Posted by bmw5

The temperature is around 8 Celcious and i always use the air condition.
In Greece the high quality fuel is the 100 octane gas.I use the 95.

The manual says that using lower grade fuel will increase fuel consumption. The manual also says to use a minimum of 98 octanes in Europe. I really don't see what the problem is here. The on board computer is not that accurate on short drives not to mention the instant readings. It gets more accurate after a couple of hundred km's.
Why not try fill up your tank, reset the odometer, do a few hundred km's and when refiling, see how many liters you need to refill. That way, we'll see how many km's you did with a given amount of liters of fuel. Good luck.