Over a period of about 3 months, my Ultra has gone from an average of 44mpg to 34mpg. It still seems to be running just fine. I'm getting my fuel from the same place every time as well. So what little thing might have changed that I can correct to get it back up there? Or is it time to trade before it craps out?

I honestly don't see or feel anything any different. But this sudden drop has me concerned. All riding is the same approximate 100 to 130 mile trips at about 72mph on the speedo using cruise control. Strictly highway miles with just the little bit of town traffic to get where I'm going and back home. Any suggestions?

Strange.

 

May just be bad gas.... or try changing the spark plugs. Dirty plugs will have a negative affect on the MPG and an easy fix

 

Tires getting smaller.

 

is your motor completely stock or...?

mike

 

I did notice a slight difference when I changed out plugs and wires...but nothing major...

 

The motor is completely stock. Only change was a Stage 1 set-up. Was like that when I got it 3 years ago.

Someone suggested change plugs. That's certainly easy enough to try. Now I wonder if I should try those iridium jobs or just stick with the Harley or Champion plug.

One thing I did just think of is the air filter. I've go caught in several absolute down pours. Of course followed by 3 days later dust. I think I better check that first. That could certainly do it. Now I wish I had thought of it sooner and not put this out until I knew that wasn't it.

Checking.......

 

The spark plug question is a crazy debate and can be scary to ask. I personally changed out my plug wires and plugs. I used Taylor wires from Amazon and E3 plugs because they were readily available and not bad price...I did notice an uptick in my mileage and the oem wire had been rubbed through in one area where it goes over the engine stabilizer link.

 

if you change, use stock spec plugs/wires.

the ecm uses ion sense and is calibrated for the resistance of the stock equipment....not so much a debate

some guys get a check engine light with as little as a change to screamin eagle plugs/wires

remember to use a little dieeletric grease in the plug wire boots and some anti-seize paste on the plug threads



so stage 1--- what "tuning compensation" do you have

any codes?

mike

 

Mix in about 6-7 oz. of Seafoam in the next tankful of fuel and see if that helps. You might need to clean your fuel and combustion systems. My Grandfather always told me, "Always start with the easiest and cheapest remedy first."

 

Don't set yourself up for the tin man spill. Actually, you must have been going downhill with a jet stream tailwind to get 44 mpg at 72 mph on a Ultra (probably over a 1000 lbs with you on there). Maybe 55 mph with a tailwind may get close. I can make my lighter Softail get 48 being careful or 38 on a frisky day. If it's running good, it's OK unless you have a silly tuner on it. If it's not running right, it will set a misfire code.