X5 3.0i fuel consumption problem
 

Hi all, this is my first post, just want to say hi to everyone. I purchased a 2005 X5 3.0i 3 months ago, so far so good. The only problem I have is fuel economy. Yesterday I filled 57 litres of gas and the trip is reading 323km. 19L/100km, isn't that a bit too much? I have no idea what's going on, my wife is driving the X5 most of the time, she said she is easy on gas pedal, I would say 50/50 city highway driving. Looks like it sucks gas more than a 5.7 GMC pick up. Any idea? Thanks in advance

Hi, and welcome to the best X5 site on the net.

19 litres/100 km is high. My 2003 3.0 step with 45000 km on it is doing 15 in pure city driving, and the best I have done on the highway is 10, but more often 11. I would check the following:
1) Tire pressures. They are sometimes set low for comfort.
2) Reset the computer by holding in the selector button while it is displaying l/100 km. Don't reset it too often, it needs to average out the consumption to show a reasonably accurate reading.
3) Verify the compute fuel consumption readout against actual consumption over a few tankfuls. It will tell you if you can trust the computer or not, in your driving conditions. A few % difference is normal.
4) Any chance someone could have reset the trip computer on you? Log the odometer each fill.
5) Check what fuel you are using. BMW calls for 91 AKI, my fuel consumption listed above is with 89, any of Shell/Esso/Petrocan/Chevron, also in Vancouver. I can't measure any difference with 89 vs 91 after repeated tests, but 87 does show a difference on mine, in driving feel and power. I expect that would translate into a fuel consumption difference, but I haven't measured it on 87.
6) If all of the above doesn't make any difference or provide any clues, talk to the dealer. They should be looking for dragging brakes (unlikely), or an engine fault.

Let us know what you find.

Jeff

Thanks for the tips Jeff, I talked to Brian Jessel BMW yesterday and they said it is a bit high. The service writer told me to use 89 instead of 91, he said all the 3.0 there they use 89 grade fuel and it actually runs better. I have already tested 3 tanks of gas and average I get the same reading. I would expect something like you have 15L/100km which is reasonable. I do hear fuel consumption issue on the 4.4 but 3.0 shouldn't be too too bad. Stay tuned...

Alex
www.128auto.com

BMW suggests 91 or higher gas. Thats what I have been following.
Can we us 89 also?
I have not seen more than 12/100 milage on mine. But I am getting around 440 miles / tank.
I am confused...

SSX5:

BMW recommends 91 because that is safest for them. There is a lot of variability in fuel quality across North America. With 91, they don't get complaints.

Your vehicle is safe on a lower octane fuel, as the engine computer will compensate by retarding timing if necessary, to avoid pinging/knocking.

The real question is whether it is worth it to you to run on a lower octane fuel than 91. It depends what the fuel is like in your area, and also the weather, the condition of your engine, etc. If you run a full tank of 89, and you can not feel any difference in the power, and you can not measure any difference in fuel consumption, then if I was you, I would keep running on 89. If all that sounds like too much trouble, then just run on 91. In my case, 89 works perfectly, and 87 doesn't. Since there is no difference between 89 and 91 in terms of power or consumption for my car, with my driving, I know that the computer is not retarding the timing, and that the fuel octane is sufficient.

Theoretically, the right fuel to use is the lowest octane that doesn't ping. Sometimes that will be 89, sometimes 91. I would be surprised if 87 didn't cause at least some performance loss. The safest fuel to use is 91, since you don't have to think about this stuff. Just remember that any octane better than that which doesn't cause pinging (or retarded timing as a result), is wasted. Higher octane doesn't give more power, mileage, engine life, etc, if a lower octane fuel doesn't experience pre-detonation.

Now, you need to decide for yourself what makes sense for you.

Oh, and for your mileage, 440 miles to a tank sounds fine from memory (we run kilometers). You indicate 12 for mileage; do you mean 12 litres per 100 km? If so, that is fine. Given that you are in the US, I was just surprised to see you quoting litres, kilometers, etc.

Alex:

Jessel should do right by you. Interestingly, they run all of their fleet on 89. The caution for other posters is that where we both live, the 89 fuel is very good, so it may in fact be more than 89.

You may want to take it out and give it a good run on the highway to see what it can do on a measured tank.

I see your business is on North Road. We are up on Westwood Plateau, a few km from you.

Good luck with the investigation.

I do not see any significant difference between 89 and 91 but I get about 2mpg less with 87.

Jeff, thanks again. My shop used to do wheel alignment for Jessel BMW for more than 5 years(Before they moved to Boundry), I know the managers very well, so I don't think they B.S. me on using 89 gas. I was reading another article on the magazine the other day, they said the new Ferrari recommend Shell 89 fuel, if you use anything more than 89, you will lose performance and gas mileage. Well.....who knows lol. I will test another few tanks of gas and do some more digging.
P.S. Please come by my shop and say hi one day. Merry Christmas!

JCL:

Back from holidays.

Thanks for your insight.
What I meant by 12/100 was for the the "Consuption1" displayed on the display. I guess it is 12 miles per gallon during the last 100 miles.
I am thiknig of trying 89 octane gas. I am using 93 now.

Thanks again.