'07 RT Gas Tank Volume?

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?

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.

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.

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

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.

5 Gallon Fillup!

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,

Thanks

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.

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.

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

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.

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

Yeah, but 2 gallons?!!! Give me a break.

heavyjetpfe said:

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

Click to expand...

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. Your call... I will go for the ease of filling my tank and getting back on the road.

Chuck

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?

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.

cwsenn said:

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. Your call... I will go for the ease of filling my tank and getting back on the road.
Chuck

Click to expand...

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.

TomfromMD said:

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.

Click to expand...

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

R1200GS same issue...

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.

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

zarinelli said:

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.

Click to expand...

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!

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.