BMW Luxury Touring Community banner

1 - 20 of 24 Posts

·
Registered
Joined
·
637 Posts
Discussion Starter #1
I have noticed that my "grandfarther" driving with high gear and low rpm`s does not make a good fuel econemy!!! So I am wondering...should I drive with RPM`s at 4000+?

What about roads with lots of turns (we have them in masses here) what RPM and gear is the ideal?

Is there a recomended list of what RPM`s at certain roads etc?
 

·
Premium Member
Joined
·
1,882 Posts
Like you, I am far too keen to get into higher gears. Also having an ST1100 which pulls from 5k revs to 50k in top (20mph-120mph) I have bad habits!
My advanced riding instructer tells me that you should ride without having to use the brakes for normal cornering. SO the engine should slow you down - meaning you need to have the revs spinning quite high.
The BMWs need far more gear changes than the Hondas!
 

·
Registered
Joined
·
1,514 Posts
I ride at 100kph on trips (maximum speed limit here) at just over 3000rpm in 5th and get 450km out of the tank dunno what that is in mpg but it is pretty good ecomomy I am sure you will get many different opinions on this one, ;)

edit just converted the figures 45.34 miles per US gallon or 5.19 litres/100km was 2 up on bike
 

·
Registered
Joined
·
699 Posts
c00k1e said:
to 50k in top (20mph-120mph) The BMWs need far more gear changes than the Hondas!
50,000RPM at the engine! What kind of gearbox does that thing have??:)
 

·
Registered
Joined
·
127 Posts
Most of my riding is between 3-4,000 rpm and my mpg USED to be 50 mpg. With ethanol I'm getting about 43 mpg.

I don't like to dip much below 3k unless on a incline as that is my comfort zone for lugging the engine. With 2 up, I raise the range from about 3,500 rpm to 4,500.
 

·
Registered
Joined
·
329 Posts
big_ed said:
4 grand is my shift point. Then whatever she wants in 5th gear.
:thumb: Same here - 4K
 

·
Registered
Joined
·
4,905 Posts
It depends how you want to ride. If you're just "putting around", who cares? Just so long as you're not lugging the engine. But if you're in the twisties and you really want to have some fun, the lower the gear the better. I've ridden through twisties for miles never getting beyond third gear ... mostly using 1st and 2nd. Keeping the revs UP gvies you maximized engine braking, and throttle control. And those are two of the most important resources when riding at a spirited pace. ;)

HTH
 

·
Registered
Joined
·
2,571 Posts
Cruising (slab): shift at 4k, keep her above 3k always.

Twisties: depends, but I tend to let her wind out, and keep it above 4k. Just rode California 36 a couple of weeks ago (140 miles of twisties) and got into 4th gear only very few times.
 

Attachments

·
Registered
Joined
·
637 Posts
Discussion Starter #10
Thanks all, good information which I will try out. :)
 

·
Registered
Joined
·
76 Posts
Always drive in the highest gear, 5th if possible and lowest RPM, without lugging the engine for best fuel econony, environmental, pollution, safety, engine perservation and wear. PERIOD!
 

·
Registered
Joined
·
712 Posts
I don't worry about the RPMs so much as the quality of the ride. Being a 5 speed, I have a tendency to use 3 rd gear a lot on side roads less than 55 mph speed limit. I use 4th from there and only use 5th on the highway.
 

·
Registered
Joined
·
4,241 Posts
Isn't the engine most efficient somewhere between the max torque and max horse power. That would be the point were the least amount of fuel is burned to convert to mechanical energy? The LT's engine seems happy at the higher rmps working easier there. I think drag has more effect than rpm. It would be interesting to see some kind of chart for best rpm vrs speed vrs mpg.
 

·
Registered
Joined
·
457 Posts
McAllister said:
50,000RPM at the engine! What kind of gearbox does that thing have??:)

I used to have one of those ST1100's and no for a fact that V-4 motor doesn't spin 50,000 rpm hahaha. Anyway the motor did love to be cranked on though and I spent a lot of time, at the higher end of its rpm band.
 

·
Registered
Joined
·
2,406 Posts
3 to 5K .... gives great passing power on tap, and great compression braking in the twisties.
 

·
Premium Member
Joined
·
1,882 Posts
Jabrown said:
I used to have one of those ST1100's and no for a fact that V-4 motor doesn't spin 50,000 rpm hahaha. Anyway the motor did love to be cranked on though and I spent a lot of time, at the higher end of its rpm band.
LOL yeh an extra 0 got in there!!
 

·
Registered
Joined
·
637 Posts
Discussion Starter #18
I was just out trying that 3k-4k and maybe gearchange after 4k rpm...and I must say WOW....... now the bike is just like a racingbike, it reacts to my small touches and is really fast...and the fuel econemy got better!!!

Now if only the darn snow can remove itself in the mountains so I can go drive the twisties! And yes some more celsius would be fine aswell :)
 

·
Registered
Joined
·
12,165 Posts
suzbmwhnd said:
Always drive in the highest gear, 5th if possible and lowest RPM, without lugging the engine for best fuel econony, environmental, pollution, safety, engine perservation and wear. PERIOD!
In my opinion, you are NOT saving fuel, and certainly not preserving the engine! The LT engine fuel efficiency range is certainly not when you have far higher throttle openings to get the same power to the drivetrain than you would in a lower gear. Anything below 3,000 rpm is not being kind to this engine at all. Crank and rod bearings work better when the surface speed where the crank journal meets the bearing surface is rather high, creating the "shear" pressure in the oil film necessary to insure the two surfaces never meet.

In large V-twins where RPM is never very high, the bearing journals are much larger in diameter to acheive a decent oil shear surface speed at lower RPM. The bearing journals on most high rpm performance engines are kept as small as possible to still be strong enough to handle the forces involved. If too large, the oil shear forces grow to a level at high RPM that can detract from the power produced. This engineering is quite involved, and a LOT of testing is done to produce the configurations that will deliver the best performance/reliability over the range of power the engine is designed for. Running either greatly above OR below the design range is counterproductive, in power, economy, AND reliablility. If you always keep the RPM low, you are likely reducing the bearing life of the engine. High throttle openings at low RPM can be more damaging to an engine than high RPM.

I tried to never let my LT drop below 3,000 RPM, and normally kept it between 3,500 and 7,000, and when just cruising around shifted around 4,500-5000, so that it did not drop below 3,000-3,500 after the shift.

Have you never experienced the power band of the engine above 5,500? That is where the fat lady really loves to sing.
 

·
Premium Member
Joined
·
3,138 Posts
Nice explanation David.

+1 on all you said.

It was the biggest thing to get used to off the Harley.

It has taken me awhile but this bike needs to be above 3500 to even have a chance at working efficiently.

I ride in 2nd 3rd on unknown twisty and maybe hit 4th on occasion. I never see 5th unless I am on slab and it needs to run at 75 or so to be happy.

Gas gage don't lie and I do better in high RPM appropriate for the terrain, then a steady slow 5th gear roll.

I would suggest covering your tach, and ride by sound and feel for a bit, you will learn your bike a lot better then tach watching.
 
1 - 20 of 24 Posts
Top