2016 RT greatly reduced mileage in cold weather

BMW RT Pilot

Premier Member
#1
So as the title states, my RT barely gets 200 miles when the temps get under say, 40-50 degrees. I travel at about 85 mph with the cruise on, road, and 2-up for suspension. I am not carrying a ton of extra cargo, about 10 pounds in each side case, and another 10 (maybe not even that much), on the rack.

This last ride I did, the bike barely got 200 miles per tank; at one point it ran out at 198 miles!

The SS3K Gold I did in December, the bike was doing better, and during the planning phase, I still set the stops to be about 200-205 miles and was needing anywhere from 5.4 gallons to 6.2 for fill-ups (which is good). On my most recent ride, I needed 6.6 gallons a couple of times (not so good)!

I am not seeing anything on the GS-911 that would indicate an issue. The bike definitely does worse in the cooler temps than when it's hot as hades- same speeds, temps in the 90s and I can push 250 miles. Drop the temps to the 50s or maybe low 60s and below and good luck.

I am using stations that meet Tier-1 fuel standards. I used to run mid-grade, but have used premium on the last couple of rides...not seeing much of a difference. Midgrade in these parts is about 89 and premium is 91-93.

Anyone else seeing these results?
 
Last edited:

Scott Parish

Premier Member
#2
Good topic. I always see a drop in winter (if you can really call it that here is SoCal) milage. I attribute most of it to the different fuel blend here in SoCal. However, if I recall; our winter blend is the standard with other states which is why our cost generally decreases a little bit as California can import fuel from other states during the winter; but not in summer.
 

Greg Rice

Premier Member
IBR Finisher
#3
Cold weather does make a difference in MPG's especially in the south.

Are you running premium gas?

Did you have a any head winds?

I used to get 210 ~ 220.
 

BMW RT Pilot

Premier Member
#4
Cold weather does make a difference in MPG's especially in the south.

Are you running premium gas?

Did you have a any head winds?

I used to get 210 ~ 220.
The man himself! :)

Yes, I be running on premium gas from Tier-1 stations. Winds are all over the place so can't really say. The biggest thing is that I can see a correlation between temps in the 50s and below and reduced range.

Maybe these stations, despite a Tier-1 rating, have 'bad' gas in the tanks? I dunno.
 
#5
Did a quick check to see if the RT is water cooled. I believe it is. My guess is that the engine is running cold. A quick fix we use up north for cars is to place a piece of cardboard in front of the radiator during the winter. When you take a ride is in cool weather try placing cardboard in front of the radiator and see if it makes a difference.

-Mark
 

BMW RT Pilot

Premier Member
#6
Did a quick check to see if the RT is water cooled. I believe it is. My guess is that the engine is running cold. A quick fix we use up north for cars is to place a piece of cardboard in front of the radiator during the winter. When you take a ride is in cool weather try placing cardboard in front of the radiator and see if it makes a difference.

-Mark
That's interesting. I've lived in the North for many, many years before Uncle Sam brought me to the South. I remember seeing diesels running with covers but not motorcycles. I'll need to see if the bike is running cold or not but I'd be concerned with the water destroying the cardboard and gunking up the radiators. Maybe something more durable would work?
 

Greg Rice

Premier Member
IBR Finisher
#7
That's interesting. I've lived in the North for many, many years before Uncle Sam brought me to the South. I remember seeing diesels running with covers but not motorcycles. I'll need to see if the bike is running cold or not but I'd be concerned with the water destroying the cardboard and gunking up the radiators. Maybe something more durable would work?
Another idea might be to run a different spark plug in the winter.
 
#8
That's interesting. I've lived in the North for many, many years before Uncle Sam brought me to the South. I remember seeing diesels running with covers but not motorcycles. I'll need to see if the bike is running cold or not but I'd be concerned with the water destroying the cardboard and gunking up the radiators. Maybe something more durable would work?
The cardboard suggestion is for testing. Cutting a piece of tarp and adding bungee hooks to hold it in place, seems like a wet weather solution.

-Mark
 
#10
Another idea might be to run a different spark plug in the winter.
LOL, when I read this, I was on my phone and didn't see from whom it was from (and it didn't help that I didn't have my reading glasses). At first I thought I was being trolled. :)

OK, I've followed in your footsteps on the rear tire thing on the RT so I'm asking if you have any info into this?
 

Greg Rice

Premier Member
IBR Finisher
#11
LOL, when I read this, I was on my phone and didn't see from whom it was from (and it didn't help that I didn't have my reading glasses). At first I thought I was being trolled. :)

OK, I've followed in your footsteps on the rear tire thing on the RT so I'm asking if you have any info into this?
Back in the day we used to run a hotter sparkplug for colder weather. I am not sure there is a better plug but if you can find one that runs a little hotter let us know.
 

STLJeep

Premier Member
#12
FWIW, my Kawasaki Voyager hates the cold too. Easily 5-10 MPG difference in the cold air. I've thought about doing the cover idea, but the bike is running so cool that the thermostat never opens up, so I am not sure how effective that would be (it would be blocking some air hitting the motor though, so the idea does have merit). I hadn't thought about the hotter plug idea. I'll have to look into that at some point.
 

Stephen!

Premier Member
IBA Member
#13
Cold air is more dense than warm air. In order to maintain the correct Fuel/Air mixture, the computer will need to use more fuel for cold air than for warm air. In a lesser degree, but still part of the equation, the more dense air will create more drag and require more power to maintain the same speed. The effects may be small, but they do figure in to the total mileage you will see.
 
#15
I know in PA that they change the fuel mixture during the winter so it burns cleaner and that blend causes lower mileage. Not sure if that is the case in other states but that could be part of the issue
Yeah I thought about that too. The only problem is that I experienced lower range when I was on I-75N through Michigan above Saginaw enroute to the UP. The temps fell into the lower 60s (had been in the 90s), with some really heavy fog at the end. I was short of my scheduled stop by about 12 miles or so.

So many variables here that it's doubtful I'll find "one thing", but maybe a series of them.
 

JAVGuzzi

Premier Member
#16
So, it looks like you are down about only 10% ( according to Greg's numbers ).

The colder an engine runs, the lower it's efficiency - it's what is called a "heat" engine. Plus colder air is more dense, and that causes more drag. Winter blend gas is 100% gas, no ethanol, so that should help gas mileage since gas has more BTU's / gallon than ethanol.

IMO, About all you can do is block the air a bit to the radiator to get the engine to run a little warmer, or somehow make the bike a little slicker ( less drag), like adding a Ryno fender flare :
 
Last edited:

cacomly

Premier Member
IBR Finisher
#17
Yeah I thought about that too. The only problem is that I experienced lower range when I was on I-75N through Michigan above Saginaw enroute to the UP. The temps fell into the lower 60s (had been in the 90s), with some really heavy fog at the end. I was short of my scheduled stop by about 12 miles or so.

So many variables here that it's doubtful I'll find "one thing", but maybe a series of them.
That there are. It could also be coincidence as you could have had a head wind and not known it. I've had my mileage tank by 10-20% because I was fighting a headwind and never realized it.
 

Stephen!

Premier Member
IBA Member
#18
That there are. It could also be coincidence as you could have had a head wind and not known it. I've had my mileage tank by 10-20% because I was fighting a headwind and never realized it.
Funny story... My K16GTL gets better fuel economy in a direct headwind than in an equally strong crosswind. I tested this one day while riding from Iowa to Minot (so essentially all the way through SD & ND). Since the roads are all N/S and E/W and on that particular day the wind was diretly from the west, I was watching my fuel economy calculator after each major turn. When I was heading directly into the 30mph wind (True Airspeed 100MPH), I was getting ~40MPG. When I would turn north and have a direct cross wind, the mileage would drop to ~37MPG. Between the friction created by being in an unending "turn" and the added drag from the wind not flowing as designed in the wind tunnel, the engine had to work that much harder to keep up a constant ground speed.
 
#19
So, it looks like you are down about only 10% ( according to Greg's numbers ).

The colder an engine runs, the lower it's efficiency - it's what is called a "heat" engine. Plus colder air is more dense, and that causes more drag. Winter blend gas is 100% gas, no ethanol, so that should help gas mileage since gas has more BTU's / gallon than ethanol.

IMO, About all you can do is block the air a bit to the radiator to get the engine to run a little warmer, or somehow make the bike a little slicker ( less drag), like adding a Ryno fender flare :
I don't think that horn would fit in with the styling of the RT, LOL.

Plus, I am long past the days when I could tuck-in. :)
 
#20
Stephen, I noticed the same thing with motorcycles but also with pickups and cars, especially worse when towing a trailer of any size. The cross winds are harder on mileage than straight on. The cross winds exert a lot of force on the side versus the front sore of pushes it around. Just my theory.

This is an interesting thread. I thought it would be because of the different blend but the fact there is less ethanol in winter, now not such a good thought.

Interesting side bar is that when I run up to Cincinnati from Dallas either on 4 wheels or motorcycle I get better mileage once I get into MO (Oklahoma if I fuel up with pure gasoline) or when I hit Memphis regardless of my route. On the way back it drops after MO or Memphis. Maybe those states actually use less than the 10% ethanol. I don't know. I do know pure gasoline is hard to find in my part of Texas. In Oklahoma it is almost easy to find.

RT, keep us up UTD if you find a cause and or solution.