cali_beemer Posted January 10, 2011 Share Posted January 10, 2011 So I just ran a tank of gas throught the bike and did a hand calc to confirm my suspicion. I got 32mpg (31.9mpg technically). I realize I dont really obey speed limits and I am hard on the throttle at every light but I dont think any of my boxxers have been that far down in fuel economy, even my 04 GS got better. I hav recently performed the following: oil change trannyy fluid change FD fluid change Valve adjust throttle body synch soaked the injectors in seafoam new tires The tire pressure is kept at 42 psi rear, 40psi front and they are Bridgestone BT-023 tires with about 1000 miles on them. I also just replaced my leaking fuel disconnects so they arent leaking anymore. The bike runs great and there is plenty of power and in line with what I would expect (its my 5th or 6th boxxer). My riding is mostly around town with some 2 lane twisies mixed in that tank. Some notes, the BBS was screwed out about 3 to 3 1/2 turns when I did the throttle synch. I also smell unburnt fuel when I start it up. Much more than any other boxxer I have owned. The bike has 15+k miles on it. I bought it with 14k miles and it had the 12k service done at 13k miles 2 years ago and got new plugs. I am temted to put on new plugs and wires to see what that benefits the bike. ANy other suggestions? Oxygen sensor? I hate to mess with anythign since the bike is running great but I only had gone 150 miles on the tank and it had only 3 bars left. Link to comment
leeinmemphis Posted January 10, 2011 Share Posted January 10, 2011 mine has a techlusion controller on it and my mileage is almost the same. Link to comment
crmdgn Posted January 10, 2011 Share Posted January 10, 2011 49 - 50 on 2004 1150 RT running around town and out on the roads of north FL and south GA between 55 - 80mph. Same as my HD XR1200 and same conditions. paul Link to comment
cali_beemer Posted January 10, 2011 Author Share Posted January 10, 2011 F = m x a Thank you for posting Newtons second law but I did pass high school physics. Link to comment
ESokoloff Posted January 10, 2011 Share Posted January 10, 2011 Not thats its the only contributor but air density is a factor in MPG. Also are you using a stock windscreen & what is it's average position? Link to comment
cali_beemer Posted January 10, 2011 Author Share Posted January 10, 2011 Not thats its the only contributor but air density is a factor in MPG. Also are you using a stock windscreen & what is it's average position? Its freezing cold right now. Its been in the high 30's to low 40's lately. Some of that time was in the low 30's. My windscreen is a slightly taller (near stock height) cee bailey windscreen and its about 2 inches up on the electronic adjustable setting. On a recent road trip, the bike was getting about 37-38 of freeway use. Link to comment
Boffin Posted January 10, 2011 Share Posted January 10, 2011 On my '04 RT the mileage took a drop of about 20% and was accompanied by uneven idle and a hesitation on acceleration. After trying the usual stuff - stick-coils, plugs, filters etc. I put an oscilloscope on the O2 sensor, which was showing a lazy response. I fitted a NGK 02 sensor and the mileage returned to normal. Andy Link to comment
AndyS Posted January 10, 2011 Share Posted January 10, 2011 +1 on boffins observations. Stick coils first and likely suspect! Andy Link to comment
Linz Posted January 10, 2011 Share Posted January 10, 2011 The best I get (with all conversions to US measurements) is 35mpg. Mine is an '02 1150RT with a techlusion and Staintune exhaust. That's being relatively easy on the throttle. I can wind the Techlusion back a touch but I get surging even with careful tuning. Linz Link to comment
BFish Posted January 10, 2011 Share Posted January 10, 2011 42mpg is about as good as i get. 47k miles. Link to comment
philbytx Posted January 10, 2011 Share Posted January 10, 2011 Went out last week and I averaged my usual 40/42 MPG. I get this most every week from both the R and RT, which are anally tuned every 6k with new plugs. This running around TX roads around 70/80mph. Link to comment
AndyS Posted January 10, 2011 Share Posted January 10, 2011 F = m x a This doesn't help as it doesnt take into account Fuel Octane rating, Air filter condition, O2 Sensor condition, plug condition, Stick coils blah blah, so where would you like us to stop. Constructive input is always best unless followed by a suitable Smilie . Andy Link to comment
Quinn Posted January 10, 2011 Share Posted January 10, 2011 My mileage has dropped off on my '04RT also. But I'm blaming the Winter gas mix. Also I need to replace the quick disconnects just in case. ---- Link to comment
boatzo Posted January 10, 2011 Share Posted January 10, 2011 My mileage has dropped off on my '04RT also. But I'm blaming the Winter gas mix. Also I need to replace the quick disconnects just in case. ---- I feel the same. I was getting around 45 on my RT, but it did drop off in the winter to around 42.I don't know if the NON ETHANOL gas we have at some stations here, has a winter formula? I'll have to check on that. I use it in all my small engines and outboard motor and sometimes fill the bike with it just for grins. SeaFoam is my best friend. Link to comment
cali_beemer Posted January 10, 2011 Author Share Posted January 10, 2011 I am suprised at the amount of people only able to get in the 30's. My 1100Rt would get 44mpg all day long and my 1200RT would get the same arund town and go up to over 50mpg on freeway. I realize the 1100 is lower cc's and the 1200 has a more sophisticated fuel injection but I would expect 40 out of my 1150. My bike is showing no signs of anything being wrong. The idle is fine and doesnt bounce, power is on par, no hesitations. Link to comment
AndyS Posted January 10, 2011 Share Posted January 10, 2011 52 miles per (UK) gallon for me (over a 63000 miles checking period). Andy Link to comment
cruisin Posted January 10, 2011 Share Posted January 10, 2011 F = m x a Thank you for posting Newtons second law but I did pass high school physics. and if you had taken the time to click on the link that is within that formula instead of getting testy about it, you would have found yet still another complete discussion about fuel mileage which may have provided you with further insight to your problem (well one of them anyway). Link to comment
cruisin Posted January 11, 2011 Share Posted January 11, 2011 F = m x a This doesn't help as it doesnt take into account Fuel Octane rating, Air filter condition, O2 Sensor condition, plug condition, Stick coils blah blah, so where would you like us to stop. Constructive input is always best unless followed by a suitable Smilie . Andy actually F = m x a is applicable regardless of all other factors. As you ease up on the agressiveness of your acceleration, you will always realize better fuel mielage. With 'a' being an exponential function it makes huge differences in fuel consumption. Also the formula is alink to another pretty comprehensive discussion that took place here just a few weeks ago; and that was my main intent -- to direct to OP to that thread with just a touch of whimsy thrown in. . . Link to comment
Deadboy Posted January 11, 2011 Share Posted January 11, 2011 You all need to realize Cali ain't happy unless he is chasing a gremlin....we went for a ride 2 weeks ago and got basically the same mileage, only difference is I didn't give it a 2nd thought while he has been fretting about it (apparently) ever since.... Link to comment
AndyS Posted January 11, 2011 Share Posted January 11, 2011 ... with just a touch of whimsy thrown in. . . Ah that's more like it. Link to comment
Starfighter Posted January 11, 2011 Share Posted January 11, 2011 45 mpg all day. 40 in cold weather 52 in warm weather at altitude. Link to comment
ShovelStrokeEd Posted January 11, 2011 Share Posted January 11, 2011 Two factors come to mind. Cold weather and winter gas. Either can drop mileage by 5-8%, combined, well, YMMV. Link to comment
cali_beemer Posted January 11, 2011 Author Share Posted January 11, 2011 You all need to realize Cali ain't happy unless he is chasing a gremlin....we went for a ride 2 weeks ago and got basically the same mileage, only difference is I didn't give it a 2nd thought while he has been fretting about it (apparently) ever since.... The 38 mpg I got on that ride was alot closer to what I would expect but since then, my around town has been 32. Thats the kind of fuel economy I would expect from my K1200RS, not an RT. I have never had such low fuel economy from a boxxer. Even my 04 GS was getting in the low to mid 40's, unless I was doing 90 on the freeway. I can only hope it improves when the temperature goes up. I am not concerned that there is any drastic problem with the bike, as I noted its running great but if I can do something simple like plug wires or an oxygen sensor to get the fuel economy back up then I will. Link to comment
eddd Posted January 11, 2011 Share Posted January 11, 2011 ...which are anally tuned every 6k with new plugs... You installed the plugs anally?? As in through the exhaust??? Please call me when you are having your next techdaze. I've go to see this for myself. Link to comment
NonComp Posted January 11, 2011 Share Posted January 11, 2011 My bikes get significantly poorer mileage when commuting in town. To the extent that I don't keep track of it anymore. I don't understand how a 3000 lb Toyota can get better mileage under similar conditions, but that is another topic. Link to comment
Boffin Posted January 11, 2011 Share Posted January 11, 2011 The number of cold-start events on a tankfull seems to have a large impact on fuel usage - I get about 240 miles per tank on my 10-mile each way commute and about 290-300 miles per tank on all-day riding. Andy Link to comment
Bruce (Bedford) Posted January 11, 2011 Share Posted January 11, 2011 Since I got my '96 r1100rt February 2010 I've done 3617 (UK) miles and used 337.13 litres of fuel = 10.73miles/litre or 48.8mpg. Very best was 55.5 mpg on a tank and worse was 40.5 mpg on a tank full. I only ride in the summer months and most miles were touring trips to la belle France very well laden! (& I'm a big chap too) :wave:I'm thrilled skinny as initially my 'impression' was about 30 mpg which didn't fit my aspirations of European touring but as soon as I set up a spreadsheet on my pda and started to record my consumption I couldn't be happier. Link to comment
RT Russ Posted January 12, 2011 Share Posted January 12, 2011 we went for a ride 2 weeks ago and got basically the same mileage Man.....there goes the opportunity for a Jenny Craig comment Being a big boy myself, I firgured everyone got better mileage than me! Link to comment
Deadboy Posted January 12, 2011 Share Posted January 12, 2011 don't forget the big windshield.... Link to comment
Dan M Posted January 12, 2011 Share Posted January 12, 2011 Low to mid 40s for me. Never light on the throttle. If it is running smoothly and your filters are clean, I'd check O2 response as others have suggested. But, the fact that you mentioned a raw fuel odor on start up may be a clue. Are your plugs sooty? Could be a sign of a leaky injector. Or if it is really running rich at all times check your temp sensor. Link to comment
cali_beemer Posted January 13, 2011 Author Share Posted January 13, 2011 I'd check O2 response as others have suggested. How would I check the O2 sensor without replacing it? Link to comment
ESokoloff Posted January 13, 2011 Share Posted January 13, 2011 I'd check O2 response as others have suggested. How would I check the O2 sensor without replacing it? I found this via a Google search. Link to comment
cali_beemer Posted January 13, 2011 Author Share Posted January 13, 2011 I'd check O2 response as others have suggested. How would I check the O2 sensor without replacing it? I found this via a Google search. Thank you. I replaced the O2 on my RS but I just bought the untit and replaced it, unsure if it would make a difference but it didnt so this time I would prefer to test it. Link to comment
NonComp Posted January 13, 2011 Share Posted January 13, 2011 What color CCP block are you using? Its the block that controls the fuel mapping. There are several that set differing programs. It is located in the fuse box and looks like a relay, although it is actually just a jumper block. Link to comment
Dan M Posted January 13, 2011 Share Posted January 13, 2011 The on car running test those guys use is about the best you can do with a multimeter. The sampling rate of those meters is too slow to be an accurate test though. It will show if it is functioning but not if it is biased rich or lean or if it is slow. Sometimes a slow sensor or the inability to achieve more than .8V is worse than not functioning at all when it comes to fuel economy. We use a lab scope to check response and switching rate but even a graphing meter will give you a much better picture of what is going on than a multimeter. When fuel is applied as those guys did in the video with propane the voltage on the graph or scope should go straight up to about 900mv. Likewise when a vacuum leak is created, it should go straight down to about 100mv.. In use if it lags the computer is constantly over compensating on mixture adjustment. Like I said before, your comment about a raw fuel odor on start up would indicate fuel leaking internally after you shut it off. If it is not leaving unburned fuel from misfiring (rough idle), you probably have a problem that is not oxygen sensor related. That assumes the fuel odor is coming from the exhaust and is not an external leak. Link to comment
AndyS Posted January 13, 2011 Share Posted January 13, 2011 I'm still suspecting a stick coil, could you borrow a pair from a chum and do a fuel check with them. Andy Link to comment
cali_beemer Posted January 13, 2011 Author Share Posted January 13, 2011 My heavy fuel smell after startup is right out the tailpipe. If I had a bad stick coil, my idle would be rough, right? My idle is perfect, and the bike is running fine. Link to comment
NonComp Posted January 13, 2011 Share Posted January 13, 2011 Maybe you are running with no CCP at all. That would ignore the O2 sensor (I think). Link to comment
AndyS Posted January 14, 2011 Share Posted January 14, 2011 My heavy fuel smell after startup is right out the tailpipe. If I had a bad stick coil, my idle would be rough, right? My idle is perfect, and the bike is running fine. No, that's the thing, often with stick coils they work fine at low load, it is only when you load the system. Also at idle, the secondary plugs are allowing the bike to idle reasonably well. Andy Link to comment
cali_beemer Posted January 14, 2011 Author Share Posted January 14, 2011 My heavy fuel smell after startup is right out the tailpipe. If I had a bad stick coil, my idle would be rough, right? My idle is perfect, and the bike is running fine. No, that's the thing, often with stick coils they work fine at low load, it is only when you load the system. Also at idle, the secondary plugs are allowing the bike to idle reasonably well. Andy But my bike seems to be running fine at all RPM's. At some RPM point, wouldnt a bad stick coil affect the way the engine runs at some RPM or anohter? It seems the people that have had bad stick coils, there has been some performance issue related. Link to comment
AndyS Posted January 14, 2011 Share Posted January 14, 2011 The experience I have with failed stick coils is that unless BOTH have failed, the bike seems to run much as normal - maybe a slight rougher feel under load, but significantly the fuel consumption goes up. The Secondary coils seem to be doing a grand job for most of the time - unfortunately masking the problem of the failing stick coils. Anyhow, if you know someone with good sticks, it's worth a try . Andy Link to comment
Dan M Posted January 14, 2011 Share Posted January 14, 2011 Do you know anyone in an independant auto shop? A gas analyzer would answer a lot of questions rather than starting to throw parts at it. High HC readings while running would indicate a misfire as with a bad coil, wire, plug or poor injector spray. High COs would indicate rich running as with a faulty O2 sensor, temp sensor or restricted intake. Excessive HCs in the exhaust (or intake) after shut down would indicate fuel leaking in. Link to comment
rad Posted January 14, 2011 Share Posted January 14, 2011 I have owned 4 Oil heads and they all have given close to the same MPG. Low end mpg, cold weather, low elevation hard riding gives the mid 30’s. High end mpg, warm weather and higher elevation slabbing gives very high 40’s and the occasional low 50’s. The only times I have been in the 30’s when not riding hard has been the result of one of three problems for me. The Mortonic FI needed to be reset. Ya know, pull the fuse, wait, reinsert, open the throttle fully two times and your done. The TPS that had moved; I reset it and all was good I forgot to put the TB nipple plugs back on after a TB sync……Silly me. Link to comment
Mr. Mixer Posted January 14, 2011 Share Posted January 14, 2011 OK, here it goes (1st post to the forum)... Bought an '04 RT at the end of August 2010 w/20,500 on the ODO and consistently got just below 40 MPG measured over multiple tanks via mi/gal as measured on the ODO. It's my first BMW, so I wasn't sure what to expect. I'm pretty hard on the throttle up to about 80 MPH, but generally don't exceed 4500-5000 RPM. Typically upshift between 4000-4500. At 24000 in mid-October, I had Bob's do the 12K service and generally go through the bike to ensure that all was well. They told me that the bike was (and I quote) "Perfect". I hoped that the TB sync etc. would increase the overall mileage I got, no such luck. Is it possible that there is simply that much variation between different bike of the same model? Link to comment
Edgar Posted January 14, 2011 Share Posted January 14, 2011 Mr. Mixer, just an aside, if you run the RPM's up to 6500 you'll find that the bike takes on a whole new character . If you use the search feature you'll find many discussions on fuel economy. I would expect that you would be in the low 40's for your bike. Link to comment
realshelby Posted January 15, 2011 Share Posted January 15, 2011 But my bike seems to be running fine at all RPM's. At some RPM point, wouldnt a bad stick coil affect the way the engine runs at some RPM or anohter? It seems the people that have had bad stick coils, there has been some performance issue related. My .02- having lived thru the "well it can't be the stick coils" syndrome and watching what others here post about stick coils on '04 RT's I have to say that if you have not replaced the stick coils and it has over 30K miles you are on borrowed time! It seems the later replacement coils are manufactured differently and I hope improved. These are VERY hard to diagnose. They will fire the plugs outside of the combustion chamber, but when installed in the engine they just won't fire consistently or at all under certain load conditions. Link to comment
cali_beemer Posted January 15, 2011 Author Share Posted January 15, 2011 But my bike seems to be running fine at all RPM's. At some RPM point, wouldnt a bad stick coil affect the way the engine runs at some RPM or anohter? It seems the people that have had bad stick coils, there has been some performance issue related. My .02- having lived thru the "well it can't be the stick coils" syndrome and watching what others here post about stick coils on '04 RT's I have to say that if you have not replaced the stick coils and it has over 30K miles you are on borrowed time! It seems the later replacement coils are manufactured differently and I hope improved. These are VERY hard to diagnose. They will fire the plugs outside of the combustion chamber, but when installed in the engine they just won't fire consistently or at all under certain load conditions. My bike only has 15.5k miles on it so I am not certian it could be one. Although I suppose I may end up buying a set to have on hand just on case. Link to comment
AndyS Posted January 15, 2011 Share Posted January 15, 2011 .... My bike only has 15.5k miles on it so I am not certian it could be one. Although I suppose I may end up buying a set to have on hand just on case. Well, that's an expensive 'just in case', I really would try to borrow a set off somebody. Andy Link to comment
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