How accurate is your fuel consumption (mpg) meter? Mine isn’t even close based on actual calculations of fuel and mileage at fill up. It seems to show around 45 miles per gallon when actual measurements and calculations are around 34.4.

 

The thread linked below started off as a thread about the Automatic Climate Control (ACC), but kind of turned into a "my mini is overly optimistic about a lot of things"...Basically, the ACC reports the car as cooler than it really is and the OBC reports the gas mileage as higher than it really is...although most folks are just 1 or 2 mpg off....

https://www.northamericanmotoring.co...e-control.html

 

My car's OBC is within 1 mpg of what I calculate. It sounds like you have your car set to UK English instead of US English with a discrepancy as high as you are seeing.

 

What do you mean by "set to UK English"? Took delivery of MINI-FRED in the UK and now in Las Vegas. The OBC seems stuck on 41.2 MPG and calculated for the last 3 tanks (mostly around town) is just under 33 MPG.

 

An Imperial (UK) gallon is bigger than an SAE (USA) gallon. There is a setting for that. This is the reason people seem to get much better mileage in the UK than the USA. The gallons are bigger.

 

My Owners Manual states that the 2009 Clubman S has a fuel capacity of 50 liters. That translates to 13.2 US gallons or 11 Imperial gallons.

Yesterday I had my car filled up with fuel as two bars (or corn kernels) just came on and my computer was giving a warning that I had 70 miles to empty. I filled that tank with 12.42 gallons which meant that I only had 0.78 gallons left in the tank! Based on my actual fuel used (34.4 mpg) I really had a little less than 27 miles till empty. So...the two bar fill up warning is really cutting it close!


Ran-o-matic,

You make a good point if indeed the car's computer is using Imperial gallons as you suggest. I looked at my owner's manual but I could not find anything stating that I could change anything specifically from Imperial gallons to US gallons. If you wouldn't mind, would you point out exactly how to do this?

Thanks,

 

That kind of error has been mentioned in threads before and it was due to it using Imperial gallons. It should be one of the settings in the OBC. Hopefully some one else will know exactly where. I have Nav and that is adjusted on the Nav screen and not in the tach's settings. Do you have the Nav system?

 

Minidrivr,

No I don't have the NAV system. The only unit settings I can find regarding fuel consumption units are l/100 km and mpg. I assumed the mpg referred to US gallons. If the mpg referred to Imperial gallons it would surely account for why my calculated values are not corresponding.

 

Even though the manual states that there is only a 50 litre tank, I have refueled the car (with about 50km to go on the computer and one or two kernels left) with more than 52 litres each of the three times I've filled it so far. I think the tank is actually bigger than they claim by a substantial amount.

 

Check the language, I think. On the giant speedo, press MENU - CONFIG and make sure LANG says US.

 

If the speedo display says AV. CON, it is set for imperial units. For US gallons it will say CONSMP. If not, change the language. On the speedo, press MENU - CONFIG and make sure LANG says US.

 

on average (13 months worth of driving and fill-ups) i get 1.3 in favor of the readout (over hand calculations)

i've gone all the way down to 0 miles til empty once or twice and my max fill up was 14.466 US gallons.

 

My OBC is optimistic by about 2 MPG+. if you search for "fuel capacity," you'll find that 14 gallon fill-ups aren't a stretch. On my Passat, it was common to go 20 miles after it showed 0 miles to empty. I haven't been so bold with the MINI yet

 

My Scan Guage is more accurate then the OBC when it comes to MPG.
The OBC seems to be off by more then 1 or 2 Miles per Gallon, and I really do not even use it any more, the scan guage has everything on it right at my finger tips so that is what I rely on

 

Do you use the fill-up function? I had my Scangauge II get way off a few times and had to reset it back to defaults to clear it. It suddenly dropped over 10 mpg.

 

Both of my MINIs have been about 2.0 to 2.4 mpg optimistic. I haven't figured out why the variation, but the range is constant.

 

Don't forget there is something like a 2gal reserve? So the actual fuel capacity is larger than 13.2. They don't state it directly but they state the 13.2 and then talk of the reserve separately. So, the actual fuel available is above 13.2 with the idea of not dipping into the reserve.

At least that's how I read the manual. Plus a tank of 11.2 gallons is a little implausible (given that there is definetely talk of a reserve).

 

My OBC is about 2 mpg over actual calculations, and the gas tank holds at least 14 gallons, based upon many previous posts on that subject.

 

Just to clarify, I'm like agreeing with you. I'm just backing it up with non-personal experience information.

 

ZugginAround should read more carefully. My 2009 Clubman manual says 13.2 gal., including a 2.1 gal. reserve.
So the computer will read ---- and you should still have 2.1 gals. left in the tank.

 

My previous tank, I did a calculation based on distance from the odometer and the number of litres I put into the tank. I can't recall the exact numbers, but the computer said I was using less fuel per 100 km than the calculations showed.

Today I filled it again and repeated the calculations. The computer showed 6.4 litres/100km; the calculations showed 6.78 litres/100km.

So, like the speedometer, it looks like the fuel consumption is also slightly optimistic. Still, the fuel consumption display is *indicative* of how your engine is running (or how your driving habits are changing).

--
Darryl

 

I have found my OBC to be pretty close, certainly within one mpg anyway. That said, I have only filled up twice now. Still on my second tank of gas at 900 miles. Gotta love that!

So a question if I may....It's winter and my car is new. Will my MPG go UP as the "warm weather gas" comes in and as my engine breaks in? Are these things REALLY a factor? Thanks.

 

I don't think this is true as I have driven on ---- numerous times and when I filled up I was never was able to put more than 13.5 gallons in.