Fuel economy is terrible!!

[The Dark Shadow]

Hiya All

I have a 2014 black ABS st1300... the fastest colour!!

Fuel economy is the pits! Today, i got 15.5km/l (about 35.5 mpg) riding from 60 to 70 mph (averaging about 110-115kph for the metric lovers). Temperature was 16-17°C and bike was fully warmed.

I am told people should get about 36-38 mpg with mixed city driving. Then at least 40 mpg but regularly about 44mpg on the highway. Yet when I do even gentle acceleration "granny" driving in the city, my mileage gets to 26 or 28 mpg (11-12km/l).

The sparks are new
valve gaps checked and in spec
throttle body vacuums right on
Air filter is still fine.
Tire pressure is fine.

I waited 18 years before I could buy this bike and now I'm really frustrated (it's my second one BTW... Last year I had a 2005 model).

Oxygen sensors are showing different voltage right and left. But both are within spec... .449v and. 566v... But these are 20-25 percent different from each other. Could this be the culprit...?

Any other ideas...? Many thanks!!

It's really frustrating me that in the city I need to fill the tank after only 200km... And highway riding I get just over 300km range... I remember the joy from the reviews about this bike was that you can get 450-500km from a tank... Maybe if you push the bike half way...?

 

[Mellow]

Does your temp gauge stay at 3 bars when you're moving? If not, the t-stat is stuck and needs to be replaced.

 

[Kevcules]

Did the fuel mileage problem happen "before" you changed any parts?
The first thing that came to mind when you mentioned terrible fuel mileage was that your thermostat was faulty. Not going up to and staying at operating temperature is a good way to get terrible fuel mileage.
Have you ever used fuel injector cleaner? Maybe your injectors are getting plugged.

Mellow is too fast!

 

[The Dark Shadow]

Does your temp gauge stay at 3 bars when you're moving? If not, the t-stat is stuck and needs to be replaced.

Thanks mate... The thermostat and coolant temperature gauge seem to be fully and correctly functional. Coolant pump does not run when starting until warm, then I can hear it cut in and out as needed. Once it's up to three bars it stays there rock steady.

 

[The Dark Shadow]

Did the fuel mileage problem happen "before" you changed any parts?
The first thing that came to mind when you mentioned terrible fuel mileage was that your thermostat was faulty. Not going up to and staying at operating temperature is a good way to get terrible fuel mileage.
Have you ever used fuel injector cleaner? Maybe your injectors are getting plugged.

Mellow is too fast!

This is the best mileage this bike gets. Before I did anything to it, and now... Hasn't really changed much.. Gotten worse if anything.

The coolant system is working properly so I can't imagine it working with the coming but not with the instruction to the engine control module.

I've used Seafoam and Lucas fuel additive (not at the same time of course).

 

[Catmandu2]

My 2012, ThunderSTruck, is pretty similar to your bike. Are your mileage figures calculated with gps measured distances,, and gas pump volume for consumption ? I don't measure in town,,, and mostly take combined readings with 80% rural riding. I have a tendency to get on the throttle a lot,,, and 16km/l is typical of a fun day. If I hyper-mile,,, I can get 20km/l Certainly higher speeds are draggy,,, so I always keep the windscreen down,,, and use a laminar lip brand deflector. Stock windscreen raised and tail case on are real mileage and handling killers. Just as your #2 fuel bar winks out,,, you have %25 of your 29l fuel load left (7.25L). I would expect to see about 350km's on the trip-ometer at that point. And, while I would be looking for the next quality gas station,,, I would know that I have over 100km left in the tank. I am pretty happy with the mileage and performance that my bike brings. Some of my buddies seem to be stopping every hour to top up their teeny tiny tanks. Hope this gives you some perspective,,, cheers,,, CAt'

 

[The Dark Shadow]

My 2012 ThunderSTruck is pretty similar to your bike. Are your mileage figures calculated with gps measured distances,, and gas pump volume for consumption ? I don't measure in town,,, and mostly take combined readings with 80% rural riding. I have a tendency to get on the throttle a lot,,, and 16km/l is typical of a fun day. If I hyper-mile,,, I can get 20km/l Certainly higher speeds are draggy,,, so I always keep the windscreen down,,, and use a laminar lip brand deflector. Stock windscreen raised and tail case on are real mileage and handling killers. Just as your #2 fuel bar winks out,,, you have %25 of your 29l fuel load left (7.25L). I would expect to see about 350km's on the trip-ometer at that point. And, while I would be looking for the next quality gas station,,, I would know that I have over 100km left in the tank. I am pretty happy with the mileage and performance that my bike brings. Some of my buddies seem to be stopping every hour to top up their tiny tanks. Hope this gives you some perspective,,, cheers,,, CAt'

What is a ThunderSTruck...? The name of your st13...?

The BEST i can get driving like a granny is 15.5km/l. If I drive anyway at all "fun" then I'm down to 14kph or less on the highway.

 

[Oldbikefixr]

Most of my 'chore' rides are three miles or under, My mileage is mid to high 20's as well, lots of traffic lights. Highway riding is around 46mph.

 

[Mikedo]

Puttering along I get 18-20. Ripping around town, stop and go, as low as 12ish. Hard on the highway, down around 14.

I'm fairly hard on the gas and last year I got 17 l per 100 (dash) (50 Mpg Imperial) for the entire ONstoc trip of around 2000plus km.

Full Granny mode = 20ish.

I suggest Seafoam and re-test.

 

[Fawlty]

Thanks mate... The thermostat and coolant temperature gauge seem to be fully and correctly functional. Coolant pump does not run when starting until warm, then I can hear it cut in and out as needed. Once it's up to three bars it stays there rock steady.

Sorry. I don't understand what you mean by 'coolant pump'. How long does it take to get up to 3 bars from a cold start? What is your tickover like when you start from cold? Should be around 2k rpm until one bar shows and should then start to drop down to around 1k rpm.

 

[ToddC]

Sorry. I don't understand what you mean by 'coolant pump'. How long does it take to get up to 3 bars from a cold start? What is your tickover like when you start from cold? Should be around 2k rpm until one bar shows and should then start to drop down to around 1k rpm.

I think he is hearing the cooling fan kick in.....

 

[ToddC]

On you next ride, after a few miles of not using the brakes.....get off and feel the rear rotor. Is it hot?
Brake drag will kill mpg.
T

 

[Arellcat]

This past weekend's jaunt saw 53.3mpg on the 220 mile run down the M6/M62, and that was screen up and top box on, and into a tricky side/head wind most of the time at about 70mph. An 80 mile blast east and west on the M62/M60 without the top box and calmer wind saw 56.4mpg, and the 265 mile ride home up the M6, including fiddly A/B roads for about 80 miles, returned 51.8mpg. The average fuel consumption meter reading improved over the course of the trip by about 15%.

In sub-10 mile urban/suburban commuting mode the bike doesn't even manage 40mpg.

 

[Willsmotorcycle]

Are you using the computer, or do you do the long math at the pump after filling?

I reset my odometer at every fill up then calculate how many miles into the gallons. I see the computer read out, but don’t use it.

Air filter, K&N or OEM, exhaust, stock or bolt on?

 

[Catmandu2]

I reset my odometer at every fill up then calculate how many miles into the gallons. I see the computer read out, but don’t use it.

The bikes mileage computer can not be used to accurately measure mileage. I use the trip-ometer,,, to only get a rough estimate of how many miles/kilometers are on each tankful between fills. An accurate measure of distance traveled has to come from my gps. The mileage computer can be used for rough comparative readings. ie: ride a couple of km's of straight flat road at posted,,, and note the consumption rate. Then ride the same km's of road (in same wind conditions and direction) at posted plus %50,,, and note that consumption rate. The two readings will give a reasonable comparison in percentage difference between the two runs,,, imho,,, CAt'

 

[The Dark Shadow]

Sorry. I don't understand what you mean by 'coolant pump'. How long does it take to get up to 3 bars from a cold start? What is your tickover like when you start from cold? Should be around 2k rpm until one bar shows and should then start to drop down to around 1k rpm.

I often run the bike at and below 10°C... So it takes sometimes 4 minutes or even 5 minutes. But when it's warmer it'll take 2 to three minutes. All seems well with the temperature regulation.

 

[ASPC]

My bike averages 44-45 MPG.

 

[ASPC]

 

[The Dark Shadow]

The bikes mileage computer can not be used to accurately measure mileage. I use the trip-ometer,,, to only get a rough estimate of how many miles/kilometers are on each tankful between fills. An accurate measure of distance traveled has to come from my gps. The mileage computer can be used for rough comparative readings. ie: ride a couple of km's of straight flat road at posted,,, and note the consumption rate. Then ride the same km's of road (in same wind conditions and direction) at posted plus %50,,, and note that consumption rate. The two readings will give a reasonable comparison in percentage difference between the two runs,,, imho,,, CAt'

My fcd measures accurately. I have checked several times. My bike has a speedo fixer on it and the speedo reads pretty close to perfect.

 

[ASPC]

Hiya All

I have a 2014 black ABS st1300... the fastest colour!!

Fuel economy is the pits! Today, i got 15.5km/l (about 35.5 mpg) riding from 60 to 70 mph (averaging about 110-115kph for the metric lovers). Temperature was 16-17°C and bike was fully warmed.

I am told people should get about 36-38 mpg with mixed city driving. Then at least 40 mpg but regularly about 44mpg on the highway. Yet when I do even gentle acceleration "granny" driving in the city, my mileage gets to 26 or 28 mpg (11-12km/l).

The sparks are new
valve gaps checked and in spec
throttle body vacuums right on
Air filter is still fine.
Tire pressure is fine.

I waited 18 years before I could buy this bike and now I'm really frustrated (it's my second one BTW... Last year I had a 2005 model).

Oxygen sensors are showing different voltage right and left. But both are within spec... .449v and. 566v... But these are 20-25 percent different from each other. Could this be the culprit...?

Any other ideas...? Many thanks!!

It's really frustrating me that in the city I need to fill the tank after only 200km... And highway riding I get just over 300km range... I remember the joy from the reviews about this bike was that you can get 450-500km from a tank... Maybe if you push the bike half way...?

What air filter do you use?