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njnear
05-31-2007, 03:07 AM
I tried to "test" my '07 RT tank volume the other day. Got to my home town with 6 miles to empty (as stated by the computer) so I chickened out and filled up. All I could cram into the tank was 5 gallons. The manual states 7 gallon tank. I figure there's bound to be some air space that's unusuable, but 2 gallons? I drove 40 miles after the warning light came on.

Or is the computer that poorly calibrated. I gotta believe the Germans are better than that.

Any real life experiences as to tank volume?

UnoRacing
05-31-2007, 03:20 AM
The bike has reserve fuel. I would bet its about 2 gallons. BMW does this for a couple of reasons; 1. They don't want you to run out of fuel on the side of some deserted road. 2. The bike is fuel injected and you shouldn't ever run the tank low. Rest assured the germans are much smarter than you think.

heavyjetpfe
05-31-2007, 05:38 AM
As it was explained to me, The 07 RT has a 7 gallon gas tank. When the warning light comes on you should be starting to burn your last gallon in what is concidered the main portion of the tank. When you get to zero miles left, you should have one gallon left in the tank. My reading were way off when I bought my bike. The service department replaced the sending unit the reset the computer. Works as above now.

cwsenn
05-31-2007, 12:08 PM
The tank holds 7.1 gallons and works as described above. You can remove the rubber stopper/insert just inside the tank with your finger and then it's much easier to top it off, I leave mine out now. I stopped once and put 7.4 gallons in my 06RT so I must have been getting pretty close to empty.
I am getting close to 12,000 miles now and so long as I'm taking it easy at say 65 MPH I can average 52 - 56 MPG which is great with the current price of gas.

Enjoy, Chuck

DaveRTS
05-31-2007, 12:13 PM
I also experienced the same situation. The dealer replaced the fuel level sender, fuel sender, and sender gasket. When the computer shows 0 miles remaining, I now top off the tank at 5.9 gallons (+/-) as compared to 5.2 gallons (+/-) prior to the repair. The repair was covered under the warranty.:thumb

HIWAYMIKE
05-31-2007, 01:16 PM
I had the same experience as Donelson! I was riding the back roads and watching my "On Board Computer" very closely. I finally stopped to gas up when it told me I had around 30 miles left! At 48 mpg avarage (according to my OBC) I figured I had less than a gallon left. I filled it up ALMOST to the top. I never try to fully top off a tank. It took 4.9 gallons! Even with a "hidden" one gallon reserve I lost another gallon somewhere!

I am almost ready to go in for my 600 mile checkup. It sounds like my fuel tank sending unit is off or mis-calabrated. I will use the feedback from this thread to suggest they fix it.

Thanks,

njnear
05-31-2007, 04:59 PM
Thanks for all the input. It's as I suspected (air and calibration issue) and will be talking to my dealer as well next time I'm in the shop.

69974
05-31-2007, 08:47 PM
I just got done with a 1300 mile trip and ran down to the 30mi left range a few times. I can get in about 5.9 gals. It took some work to get there. I could fill the neck about 5 times and it would drain into the tank. When it wouldn't drain I rock the bars back and forth and then it would, then I figured I was done.

So it looks like it is 5 to yellow, 1 more per the computer, +1 for safety.

cwsenn
06-01-2007, 12:18 AM
Out of curiosity, why don't you guys remove the rubber neck inside your tank so you can top it off easily before you all go to your dealer feeling certain you have a problem? I don't believe all, if any of you have an issue. I believe BMW has put out too many RT's without this issue for you all to be experiencing the same problem. I would be interested to hear back from you if you would give it a try.

Just my .02 cents,
Chuck

njnear
06-01-2007, 02:06 AM
I agree. Just like to know what I actually have and 5 gallons seemed way too low. Therefore my presumption was I had some air in the tank and there was some error on the computer.

Will report back.

heavyjetpfe
06-01-2007, 06:13 AM
The rubber block in the tank is there to prevent you from topping the tank, you need to have a certain amount of air space to allow for fuel expansion if the bike is sitting in the sun or operated in very hot areas. By removing the stopper you risk forcing fuel under pressure caused by expansion into the fuel system and the emissions systems. Same thing goes for cars and trucks if you fill past the auto stop you risk fuel pushing through the emissions system. I'm not a mechanical engineer, that's just the way I understand the systems

njnear
06-02-2007, 02:14 AM
Yeah, but 2 gallons?!!! Give me a break.

cwsenn
06-02-2007, 03:00 AM
The rubber block in the tank is there to prevent you from topping the tank, you need to have a certain amount of air space to allow for fuel expansion if the bike is sitting in the sun or operated in very hot areas. By removing the stopper you risk forcing fuel under pressure caused by expansion into the fuel system and the emissions systems. Same thing goes for cars and trucks if you fill past the auto stop you risk fuel pushing through the emissions system. I'm not a mechanical engineer, that's just the way I understand the systems

I have had mine out for at least 10 months with no issues. When I do fill up I am always driving at least another 15 miles which will consume the difference. Worse case scenario the fuel would expand and go out the overflow in the top of the tank. I will never put mine back in and filling the tank is quick and easy without the rubber insert in the tank. :dunno Your call... I will go for the ease of filling my tank and getting back on the road.

Chuck

rebus
06-02-2007, 03:44 PM
My dealer told me "Of course I would never recommend someone modify a piece of their emissions system, but 'some' people remove the rubber spacer from the fill tube to allow more fuel in the tank..." Seems the dealer thinks its not a problem to do this, and I have had no issues.

My '05 RT takes 5.5 - 6.0 gallons when the OBC reads "0". I consider the remaining fuel in the tank to be my hidden reserve, although I have never run it down to empty. Anybody tried doing that?

njnear
06-02-2007, 05:04 PM
Here's another data point.

Low fuel light came on at about 45 miles to empty. Drove another 5 miles and filled up. Removed the rubber stopper; crammed 5.35 gallons in.

That's a bit better. Will be leaving the stopper out.

Tom K.
06-02-2007, 07:03 PM
I have had mine out for at least 10 months with no issues. When I do fill up I am always driving at least another 15 miles which will consume the difference. Worse case scenario the fuel would expand and go out the overflow in the top of the tank. I will never put mine back in and filling the tank is quick and easy without the rubber insert in the tank. :dunno Your call... I will go for the ease of filling my tank and getting back on the road.
Chuck

Chuck, are you saying that with the insert removed, the gas pump won't repeatedly cut off when you are still as much as 2 gallons from full as mine does now? If so, I'll take it out immediately.

cwsenn
06-03-2007, 02:36 AM
Chuck, are you saying that with the insert removed, the gas pump won't repeatedly cut off when you are still as much as 2 gallons from full as mine does now? If so, I'll take it out immediately.

I'm saying its much easier to gas up and top off your tank. Try it for yourself and if you don't like it put the insert back in. It does give you a little larger hole to gas up into and I believe it's considerably easier.

Chuck

ZARINELLI
06-03-2007, 03:13 PM
I posted on the ADV board on this as well (got a couple of smartass replies, so didn't push the issue over there...)

My 07 R1200GS has a published tank volume of 5.3 gal, with the reserve light supposedly coming on when there are 1.1 gal left. What I found is that my gauge is highly non-linear. After filling up, the trip computer will show a RANGE of around 230 - 250 miles (I usually ride easy at 60-70mph) with an indicated (and calculated) ~45-47mpg consumption.

Now the weird part. The gauge goes down slowly for the first 120-130 miles, then starts 'running' down fast - by 155-165 miles my reserve light comes on. I rode down to 3 miles once (usually I chicken out before hitting 10 on the RANGE), and was only able to fill 3.975 gal in the tank! In fact, I have never been able to fill in more than 4 gal...

The funny part is that, on my previous 05 R1200GS, which did not have the trip computer, the reserve light came on consistently around 200-210 miles, and I got 48-50 mpg (using Amsoil 20W50, and well broken in at 40,000+ miles).

I did remove the rubber filler neck, but it did not make a difference in the readings... It appears that, as others have indicated, the light comes on with at least 2 gal left in the tank; when the RANGE reads '0', there is still at least 1 gal of fuel left in the tank. Huge problem? No. Annoying? Yes, especially considering you pay extra for the trip computer. :nono

[P.S.: Some say the issue comes from the way the GS' tank is shaped... Go figure]

Tom K.
06-03-2007, 08:31 PM
The gauge goes down slowly for the first 120-130 miles, then starts 'running' down fast - by 155-165 miles my reserve light comes on.

For what it's worth, the OBC on my RT is similar. It reads about 350miles (7 gal@50mpg) after a fill but begins to drop rapidly with about 120 remaining. And each of the 3 BMW cars I've owned over the past decade has also had the same, non-linear miles to empty OBC readings.

However, I have found that the OBC instantaneous speed readings are pretty accurate and may be used to obtain the speedo error. Win some, lose some!

njnear
06-12-2007, 01:52 AM
Just another data point.

Rubber stopper is out of tank.

Light came on approx. 45 miles to empty.

Drove another 17 miles past 0 to empty (did not run out or sputter).

"Crammed" 6.2 gallons in.

marcopolo
06-12-2007, 09:37 PM
The fuel gauge on the RT can be recalibrated by the dealer. It goes something like this: first, they have to empty the tank (so don't go in with a full tank); then they must let the fuel sensing strip in the tank dry; then they pour back in a measured quantity of gas -- whatever you want the reserve to be; finally, they hook up the bike to the diagnostic computer and "instruct" the bike to use this new fuel level as the reserve amount. I, and many other R12RT owners, have had this done under warranty.

ZARINELLI
06-25-2007, 11:24 PM
... they hook up the bike to the diagnostic computer and "instruct" the bike to use this new fuel level as the reserve amount. I, and many other R12RT owners, have had this done under warranty.

I will have my dealer go through this procedure at my next service (should be later this week); will be interesting to see what happens. I went out last week-end, and took along a 1 gal gas container - just in case my 'intuition' should prove wrong :D.

Ran the bike ('07 R1200GS) past the "---- RANGE" mark for 32 miles. Stopped at a gas station to refuel. GPS showed 236 trip miles, and I put 4.759 gal in. OBC showed 49mpg, I calculated 49.59mpg. That left me with around 0.5 gal in the tank, for a real "Till Empty Range" of almost 263 miles.

henzilla
06-26-2007, 04:31 PM
I tried to "test" my '07 RT tank volume the other day. Got to my home town with 6 miles to empty (as stated by the computer) so I chickened out and filled up. All I could cram into the tank was 5 gallons. The manual states 7 gallon tank. I figure there's bound to be some air space that's unusuable, but 2 gallons? I drove 40 miles after the warning light came on.

Or is the computer that poorly calibrated. I gotta believe the Germans are better than that.

Any real life experiences as to tank volume?


I was crossing farm country this past Sunday in a rainstorm and saw I had 17 miles of fuel left on display,light had come on at 50... hit the GPS for fuel options...16.5 to fuel..YIKES... I pulled into station after easing up to "conserve" fuel and arrived with 1 showing on display. I topped off as usual and only got 6.1 gallons in the tank...guess I could have gone another 50 miles or so. Still not sure of my limit...but did not feel good not knowing true range

dlowry
06-28-2007, 12:54 AM
I rarely make it to "empty". The SO's R1200CL has a tiny tank so every time we stop for fuel, I top off. I do get better economy on the RT - 12 liters for her, 10 for me... Having said that, the most I've ever squeezed in to the tank was 22 liters, or about 80% full. Everyone says I should run it out, but I hate doing that to an injected vehicle.

maxfrankel
06-29-2007, 01:51 PM
All this discourse about a topic that is so easy to resolve logically and empirically.
1. The tank holds 7.2 gallons just as BMW states!
2. The "miles remaining" readout is an estimate based on fuel consumption rate since last reset, but it is an estimate to a reserve remaining quantity that varies marginally from bike to bike due to calibration differences, and varies very slightly from tank to tank within a bike due to the "sloshing factor".
3. Accordingly, to the "miles remaining", you must add some number of miles based on your recent fuel consumption rate and the "typical" quantity of fuel remaining in your tank on your bike given the status of your BC's calibration.
4. The best way to determine the actual miles remaining when your BC states "0" is to simply run the bike dry, under "average driving conditions" while carrying a small quantity of fuel in a gas can. Do this a couple of times to get an average. It won't hurt your bike to run out of fuel!
5. Obviously the total miles you get from a tank will vary depending how full you fill the tank. Sure you can cram more fuel in by removing components BMW designed into the fuel system for safety, but for most of us, the real issue comes into play only when needing to stretch for that next gas station during the final 50 miles or so of capacity.

ZARINELLI
07-04-2007, 02:16 PM
I will have my dealer go through this procedure at my next service (should be later this week); will be interesting to see what happens.

[...]

Asked dealer to perform the procedure above. Mechanic claimed he couldn't find an option to reset the "RESERVE" in the software, so they didn't do it.

Anybody here know what the setting is called to reset the RESERVE in the software?

ZARINELLI
07-04-2007, 02:22 PM
[...]
5. [...] Sure you can cram more fuel in by removing components BMW designed into the fuel system for safety, but for most of us, the real issue comes into play only when needing to stretch for that next gas station during the final 50 miles or so of capacity.

Interesting conjecture...

On my bike, when the contraption was in there, the last segment on my fuel gauge never came on - almost as if the tank didn't get filled all the way. No change in when the reserve light came on, though. After removing the thing, the last segment on the fuel gauge comes on every time I fill the tank. Already had this removed on my 05 and never had any 'safety' issues... :D

wezul
07-04-2007, 02:32 PM
I've had similar "fibs" from "miles to empty" on my '07 RT and my F800ST. Ran the F down to zero, assumed that it would start sputtering immediately but was able to run another 5 miles or so to gas up, still don't know how much I had left in the tank.

Back to the RT, a couple nights ago I'm going to gas it up and I put it on the center stand, as usual. I fuel up to the point that the pump kicks off, then do a couple short squeezes and again both times the pump shuts off. Full, right?
Back on the road and the computer takes it's usual few seconds to calculate the fuel in the tank. The display reads just below full. This perplexes me as this is not the first time this has occured.

Have you had a similar experience? Not that it's all that critical, just mildly annoying.

(Oh sheesh, just read some previous posts and I think I understand now, sorry)

ZARINELLI
07-04-2007, 02:42 PM
... very similar. The funny thing is that my OBC's mpg is dead on (checked manually, using GPS data to compare), so I look at my average mpg's and do a quick calculation to see actual DTE - and essentially ignore the whole RANGE display.

Works pretty well - but yes, on an $18,000+ bike, you'd expect the fuel gauge to work correctly. Annoying is the right term. On the other hand, that's my only beef with the bike, so I think I can be happy, overall :laugh


I've had similar "fibs" from "miles to empty" on my '07 RT and my F800ST. Ran the F down to zero, assumed that it would start sputtering immediately but was able to run another 5 miles or so to gas up, still don't know how much I had left in the tank.

Back to the RT, a couple nights ago I'm going to gas it up and I put it on the center stand, as usual. I fuel up to the point that the pump kicks off, then do a couple short squeezes and again both times the pump shuts off. Full, right?
Back on the road and the computer takes it's usual few seconds to calculate the fuel in the tank. The display reads just below full. This perplexes me as this is not the first time this has occured.

Have you had a similar experience? Not that it's all that critical, just mildly annoying.

(Oh sheesh, just read some previous posts and I think I understand now, sorry)

njnear
07-05-2007, 02:16 AM
All this discourse about a topic that is so easy to resolve logically and empirically.

Mr. Spock would not think the computer that miscalculates miles to empty logical, nor shoud the Germans. I, quite frankly, am mildly disappointed with the OBC in an era where we can cure spark knock in milliseconds, but can't link a mass flow and level gauge.

The OBC is dead on (at least to my error level and comfort factor) when it comes to calculating the gas mileage. Why can't the level be linked and recalculated. What's that take? A Cray supercomputer?

Now that would be "quite logical."

kbasa
07-05-2007, 05:40 PM
Mr. Spock would not think the computer that miscalculates miles to empty logical, nor shoud the Germans. I, quite frankly, am mildly disappointed with the OBC in an era where we can cure spark knock in milliseconds, but can't link a mass flow and level gauge.

The OBC is dead on (at least to my error level and comfort factor) when it comes to calculating the gas mileage. Why can't the level be linked and recalculated. What's that take? A Cray supercomputer?

Now that would be "quite logical."

It seems to me that the problem is just calibration.

100394
07-05-2007, 07:26 PM
Ran my 06 RT to 5 miles and filled up, still have rubber stopper in and rocked the bike a little got 6.35 gallons in so I don't consider that too bad, gives me a range of about 250 miles. by that time I'm ready to stretch my legs.

njnear
07-06-2007, 01:41 AM
Ran my 06 RT to 5 miles and filled up, still have rubber stopper in and rocked the bike a little got 6.35 gallons in so I don't consider that too bad, gives me a range of about 250 miles. by that time I'm ready to stretch my legs.

Which means you really should have approx. .8 gallons left and enough gas to go another 40 miles.

DocZ
07-11-2007, 01:57 PM
I do like the BC, but the fuel level indicator on my newish R12RT is quite the pessimist. Mine shows empty after about 5.5 gal. and is in line with others experience here.

I plan to do exactly nothing about it and use the old trip meter method - after all, that has worked well for me since the early Silurian era....

What I like best about the whole BC thing is the temp reading anyway.

podsobinski
07-12-2007, 06:34 PM
Gas gauges, low gas lights and odometer readings. . .remember the Silurian Period times way back when we didn't even have a reset on our odometer and we had to look in the gas tank and shake the bike to see how much gas we had. Now we are complaining that our computer on the RT is not in perfect harmony with the total volume of the gas tank. . . man have we come a long way or are we getting so spoiled with technology that everything has to work perfect to our satisfaction or you take it to the shop. I guys I think every bike has little differences, get use to them and enjoy. The digital gas gauge is great, the distance to empty (or reserve) is great and then the flashing ! and little gas pump is cool. . .come on guys mellow out and realize how far we have come in 48 years of riding . . . Ducatic 250 Monza's rule!:dance

Gpodzo
R1200RT
R1150GS
XR650L

njnear
07-18-2007, 02:38 AM
Now if I could only get used to my Windows crashing.....

1analguy
07-18-2007, 12:52 PM
My fuel gage was useless until the 600-mile service, when I had them recalibrate it. When they returned the bike, there was under 2 gallons in it, so I decided to see what the ultimate capacity of the tank really is. I put a gallon in a can into the top case and then rode the bike empty. As good luck would have it, it sputtered and killed while idling at a stop sign across a quiet intersection from a gas station. I pushed it over to a pump, put it on the center stand, popped the rubber sleeve out of the filler neck, and filled it to the bottom of the metal sleeve. It took 7.48 gallons.

The Miles-To-Empty value is still not accurate enough to be of any use. However, the bar-graph fuel indicator is fairly reliable now. When the very last pixel at the bottom of the bar disappears, there's about 0.7 gallon left in the tank. I consider this to be my "reserve", and the MTE is long past 0 miles at this point. The yellow triangle comes on with about 1.5 gallons remaining. I really wish I could swap that MTE readout for a numerical oil temperature value...