why does my On Board Computer say that my average MPG is 21.8? Is that normal?

I do know that I can get about 175 miles off a half a tank, then the last half goes very very quickly.

Any ideas?

 

Try resetting the computer, but if you are in fact getting 175 miles out of half a tank then it is certainly on the low side.

Check tires, air filter, e-brake, what is your current mileage?

 

Usually by half tank I get about 200 miles, if I recall, I will pay more attention next time I fill it up.

 

I am at 2300 miles.

what is the average you get for miles off a tank?

 

I'm usually "on pace" for abotu 450-475, but I never run empty. I fill with 2 or 3 bars left, and it's usually in the mid-to-high 300 miles at that point.

 

When cold weather comes, everyone complains about this. Check the air pressure in the tires! The OBC is not as accurate as doing the math.

 

The little markers mean nothing as far as mpg is concerned; ditto OBC. You have to divide actual miles traveled by actual gallons of gas purchased.

 

hum. I don't think I have ever hit 300 though. Not even when I got the car in the late summer.

I am usually about 250 when I get to marker number two left in the tank.

Right now I have 4 markers left, and only 210 miles on the tank.

 

Yes, You are right, By actually dividing miles driven by how many gallons of gas I put in, the Avg. is about 30mpg.

What I mean to say is that after 5 lights are out, out of 10 it is about 200 miles in mine, maybe 220 miles.

 

I tried doing the "light" thing, but I've found it totally inaccurate. The first bar goes out at about 125 miles.

 

My mileage dropped a bit lately.

I've been running 37/36 lbs tire pressure. Checked it a few days ago after the weather tuned to frigid below 50 F temps (remember, this is California) and found they were down to 33/32. I would guess that in areas with real winters, the drop would be even greater.

 

That's because there is x amount of gas in the filler neck, so you have to drain through that before it registers on the gas gauge. Same reason a lot of people find they fill more than 13.2 gallons in a 13.2 gallon tank.

 

380-400 miles is what i normally get out of a full tank.
averages to 28-30 mpg depending...

 

Is anyone using that E85 fuel? That's supposed to cost about 5-10% in MPG. Also, has anyone compared MPG for Regular vs. Premium fuel?

 

I have 4000 miles now and get 34 on average with a 50/50 mix of city and highway miles. I get almost 500 miles to a tank. I always use 93 octane, although I get it at cheap places (ie costco). I started at 29 mpg and have worked my way up with the mileage. Also I randomly hand check my mileage with the obc and it is always dead on.

 

I don't have it handy right now, but I seem to remember seeing something in the owner's manual that said not to use E85.

 

From page 85 in the PDF version of the manual:

 

Keeping tire pressure between 33 and 36, with just over 4000 miles on my MCS, and using 91 octane exclusively I get well over 400 to a tank (and fill up when the bars turn red). The OBC says I'm getting over 36 mpg, but actually calculating it, it comes in at the 34 -35 mpg range. Little "city" driving and I'm more conservative than aggressive behind the wheel. Although, I do get on it from time to time.

 

I have had my MCS since Aug and the best I've ever done was 425 on a tank. I drive about 70% city and 30% highway. Maybe I'll try driving totally conservatively for a tank and see what comes up. Check the tire pressure....etc. I don't know how some of you get "almost 500 miles out of a tank"? Especially in Austin traffic.

 

Re: E85 -- a single tankful of 93 octane-but-unmarked-as-E15 destroyed the fuel pump in my R56 within an hour of leaving the station, and voided warranty for the repair, which included fuel system drain and cleaining, including injector cleaning.

Problems like this we cannot prevent, but purposefully using anything over E10 with the Prince engines and fuel system would be foolhardy.

(The oil co. settled, but it required polite persistence.)

 

yep, tank lights stay on long initially and then count down progressively faster on mine '07s. OBC is a bit more optimistic about fuel mileage than my own miles/gallons calc, which comes out at about 28mpg with quite a bit of very short commuting. Also the OBC projected remaining miles tend to be fairly short ones...

Uli

 

My gauge doesn't move until I have about 100 miles on the trip odometer. When the fuel light comes on at two bars I need to gas up right away and usually get 12.5 gallons or so into the tank. Since my other vehicle is a Triumph motorcycle with no gauge I'm used to driving more by the odometer than by the gauge but it would be nice if the fuel gauge was more accurate. Both the Mini and the Bonneville America have speedos that are 7-8% off too.

 

Did you guys see the 20/20 segment yesterday, where Johm Stossel deliberately ran out of gas to see how accurate the fuel countdown computers are? It turns out he went about 30 miles or so--can't remember how many--AFTER the computer counted down to zero. This was on an American car, and it was pointed out the Europeans like an exact number without a cushion. I wonder what OBC program they use in the MINI.

 

I missed it but I can tell you that I have pushed my car down to 14 miles left per the OBC...scary feeling. The weird thing is how these numbers seem to be all over the board, I mean someone ran out of gas w/ 30 miles left per the OBC.

 

There is another thread here somewhere with reports on running out of gas with more than 30 miles left on the OBC. Personally, I wouldn't go past 60 if I could help it.