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View Full Version : Just how inaccurate is the fuel gauge?



kidtwist29
04-18-2009, 04:31 PM
I bought an R1200R last week and hadn't ridden it much until today. While returning from a fifty mile ride I ran out of gas even though the fuel gauge showed nearly half a tank left. Is that unusual? I had to push the bike about ten painful blocks to a gas station. Almost dropped it a couple of times. Not a fun way to spend the morning. :cry

Whenever I've purchased a motorcycle before the dealer made sure it had a full tank of gas before I rode it home. This time I only had about 60 miles worth. Is it not BMW dealer policy to fill the tank or did mine just screw up?

Despite the gas problem, I'm having a great time with the bike.

henzilla
04-18-2009, 10:42 PM
Not trying to be a smart-a**
I have only once gotten a full tank upon purchase of a new bike. I don't think there is a corporate policy, I may be wrong. Was it used/new?
Kinda puts a new meaning to "buyer beware" to check all systems prior to riding. You should have at least seen the flashing warning light at around 50-70 miles to go...Unless your gas guage software/strip are malfunctioning.

podsobinski
04-19-2009, 12:09 AM
Being from Colorado, there was no deals around for a trade with my 06 RT to a new GSA. Internet search found Gateway BMW of St. Louis would deal. So off I went, did the exchange and heading home. The salesman told me he filled it up but the gauge registered empty. Well a 100 miles later and waiting for a reserve light to go on I stopped and filled it up. Guess what, 2 1/2 gallons to fill it and the guage still registered empty. Well no bother, I used the trip odometer and on the first service in Colorado Springs they replaced the fuel sensor and no problem after that.
Now if the weather breaks we can start riding!

gpodzo

professor
04-19-2009, 12:27 AM
When the guage says zero miles, I have about a gallon left in the tank of my '07 R1200RT. So when it says I'm empty, I can still ride at least 40 miles.

Sometimes it does act weird, though. The other day I filled the tank and after I began to ride, the bar went to the top (or as close as it ever gets) but the miles-to-go indicator didn't change. Then after riding two or three miles, the number went up about ten miles. I probably rode twenty miles or more before it finally read 275 which is around what it normally says when I fill up. I'm about 1,000 miles away from my 12K service so I'll have them check it out then. Other than that, it seems to work fine.

I rode about 40 miles today in a light rain and loved it. It could be my imagination, but I'm pretty sure the RT loved it too. :laugh

amiles
04-19-2009, 05:32 AM
perhaps until you become familiar with the machine you should use the "cave man" gas gauge method via your trip odometer.

I am sure that you must have heard of this technique from antiquity whereby you reset the TO at each fill and learn the approximate typical distance that a full tank will take you.:doh

Won't correct your gauge but it might save you the "walk of shame"

RACEYDOG
04-19-2009, 06:57 AM
It is supposedly the fuel strip causing the problem. I have had one serviced already and it actually got worse. I am taking it in this week to have it worked on again. Common practice (apparently) is to clean and dry the fuel strip and then reset the computer. On the third attempt, they will replace the strip. That's my experience anyway.

kidtwist29
04-19-2009, 03:40 PM
It is supposedly the fuel strip causing the problem.


Yeah, I went to the dealer yesterday, and that's what they said.

Since I refilled the tank, the gauge now correctly shows it as full, so I guess it's only partially malfunctioning. Or maybe
it was just a one time thing. I'm going to wait till the first service and have them fix it then if it's still a problem.

DXMENON
04-27-2009, 02:25 AM
the gauge is not very accurate. when the gas light goes on, i still have 2.0 to 2.5 gallons in the tank. I drive it to zero (miles left till empty according to the computer) and start looking for a station. the only way to be certain is to go by the odometer and not trust the gas gauge.

I am going to recommend to bmw that an accurate gas guage should be an upgrade option. They might have it in their heart to make this option less than $1,000. Perhaps $999.99. :deal

Safe riding.

LONERANGER
04-27-2009, 11:43 AM
I have a friend who just bought a new Buell XB12XT and it does not come with a fuel gauge. He didn't notice it when he bought the bike as he assumed it had one.

Semper_Fi
04-27-2009, 04:15 PM
......the only way to be certain is to go by the odometer and not trust the gas gauge.

Safe riding.


My odometer is off by 4% - still more accurate than the fuel gauge.

Depending on the situation i just fill up at 3/4's indicated - seems to work well for me.

You would assume that on an 18K bike and 1mph controlling accuracy for the cruise control (verified by gps) they could make an accurate gauge.

Done with rant - thanks

mpmarty
04-27-2009, 08:44 PM
I guess I'm just lucky. My 04 1150 RT was spot on and so is my 06. When it lights the light I've got about a gallon and a half left.

ROGSLATER
04-29-2009, 03:54 AM
I bought an R1200R last week and hadn't ridden it much until today. While returning from a fifty mile ride I ran out of gas even though the fuel gauge showed nearly half a tank left. Is that unusual? I had to push the bike about ten painful blocks to a gas station. Almost dropped it a couple of times. Not a fun way to spend the morning. :cry

Whenever I've purchased a motorcycle before the dealer made sure it had a full tank of gas before I rode it home. This time I only had about 60 miles worth. Is it not BMW dealer policy to fill the tank or did mine just screw up?

Despite the gas problem, I'm having a great time with the bike.

My 1200RT has very accurate fuel gauge. I did not realise there was no fuel in the 70 miles between Buffolo and Gillette on I-90 last July. At the half way point the GPS advised nearest fuel 35 miles in either direction. Miles- to- go on fuel read out on the BM said 29 miles at current rate of knotts. I kept clicking back the cruise control until at 40 mph the miles to go on the bike and the GPS read identical.
As I ran down the first off ramp at Gillette the bikes engine stopped just as the miles to go read out clicked to zero, the GPS read 300 feet to go. I pulled in the clutch and whized off the ramp, up a small rise and rolled to a halt alonside the first pump. It took 7.1 gallon to fill the tank, how accurate is that then.

Roger Slater

professor
04-29-2009, 08:43 AM
That is amazingly accurate, Roger. My low fuel light comes on when the guage reads about 37 miles to go. At zero, I still have about a gallon in the tank. So when the light comes on, I can still ride at least 70-80 miles and when it hits zero, I can still ride at least 40. I kind of like it this way. I act as if zero means zero and try not to let the guage get below 20 before refueling. That way I always have a healthy reserve.

My problem has been mpg. It seems no matter how I ride, I get 38.something - usually close to 39. Others tell me they always get close to 50 ('07 R1200RT). I just had the 12K service done. The bike seems to be running really well. I'm hoping the mileage has improved. I'll find out soon.

ROGSLATER
04-29-2009, 04:56 PM
That is amazingly accurate, Roger. My low fuel light comes on when the guage reads about 37 miles to go. At zero, I still have about a gallon in the tank. So when the light comes on, I can still ride at least 70-80 miles and when it hits zero, I can still ride at least 40. I kind of like it this way. I act as if zero means zero and try not to let the guage get below 20 before refueling. That way I always have a healthy reserve.

My problem has been mpg. It seems no matter how I ride, I get 38.something - usually close to 39. Others tell me they always get close to 50 ('07 R1200RT). I just had the 12K service done. The bike seems to be running really well. I'm hoping the mileage has improved. I'll find out soon.

It would seem I am lucky with the uncanny accuracy on my 05 RT. More than I can say about the ambeint temp read out before I changed the senders position from factory installed position.
Re the "miles to go" and the fuel warning light. I believe that when the fuel light comes on the miles to go read out will be based on CURRENT consumption. If I am howling along into a head wind and uphill the miles to go can be 35 as the light comes on. Under normal legalised speed it will read 45 to 52 miles to go.
Your heavy consumption does not seem normal. I average 45 to 52. I find lower octane regular pulls the fuel mileage down due to the anti knock sensors pulling back ign advance. Riding gently seems to have little negative effect, probably cos the knock censors are having nothing to do.

Roger Slater out on the frontier

professor
04-30-2009, 09:14 AM
The 12K service made a difference. I rode about 100 miles yesterday - a combo of some stop-and-go traffic and highway at 65-70 kicking it up to 80-85 while passing a couple of trucks. My overall mileage was about 48 mpg. That's 10 mpg better than I've ever gotten before.

The bike also seems to be running a little smoother and possibly a little more responsive than before the service.

I'm very pleased.

mistercindy
04-30-2009, 04:00 PM
I don't know how similar the R12R gas gauge is to the older 12GS ('05) gas gauge, but on my 12GS the gauge is worthless up to the moment the "reserve" light pops on. Once the reserve light pops on there are four bars. After a while one bar disappears leaving three. Then two. Then one. I get a remarkably consistant 10-11 miles per bar (ie., ~40-45 miles with the reserve light on). So while the gas gauge is virtually meaningless until that light pops on, once it comes on its very predictable.

So, if predictability is most important when you're low on fuel, my 12GS gauge is great.





I have a friend who just bought a new Buell XB12XT and it does not come with a fuel gauge. He didn't notice it when he bought the bike as he assumed it had one.
I rode for 20 years without ever having a gas guage. I've had a number of bikes that didn't even have a trip.