I dunno' I just gas up (with required premium unleaded) when I need to and go..don't spend a second more time thinking about it..ride it the way I want and mpg is what it is whatever that is I don't know or care

 

I ride like Mr Webb.Keep the bike well tuned,ride the way you want and not to worry about the MPG.Mileage will be acceptable-enjoy the ride.

 

I tend to side with the just gas it up and go crowd. As long as the engine is running great and I dont see a significant decrease in the miles I go between fill ups I just ride it. I guess if a person bought a bike to cut down on their fuel usage it would be important but for me most of the gallons I pour into the HD are actually additional gallons of fuel I purchase.
There are some miles that I put on the bike that I would be putting on my vehicle if I did not have a bike but most of my bike miles are for fun and are all additional miles that I put on only because I want to go for a ride. For me the bike adds to my yearly gas expenditure over what I would spend if I did not have a bike

 

So is the consensus that the thermostat is broken or is there a design flaw?

 

I seriously doubt anyone believes there is a design flaw..he's just duct taping cardboard to his cooler or something because his perception is it HD messed up and the engines won't get to 185 degree oil temps in cold weather, or something like that..both mine and my wife's work great..he also mentions a variance in your mpg is a good indicator that it's time to clean your air filter...waaaay too much brain power being expended here imo..keep bike serviced as needed, put gas in, ride..rinse and repeat..what I don't get is why even worry about mpg unless your goal is to always maximize it then just set your cruise control at 60 the whole trip..on all the trips we go on we just have fun riding and gas is the least expensive part of them after food, drinks, hotels, t shirts and dropping hundreds in Casinos..LOL

 

Funny. People can see the danger of having too high oil temps based on zero experience with there being an actual problem and buy 300 dollar devices to save the bike from itself because HD must have done such a bad job designing such engine and hell it's not hurting it right - throwing 300 bucks at a non-issue....BUT at the same time cannot see what most truckers and long haul drivers going through cold weather have known since the dawn of the steering wheel... cold engines burn/spray more fuel when stuck in enrichment mode and thus washes rich mixtures down cylinders contaminating the oil etc and etc.

The way to correct this as known to many... cardboard or vinyl over the radiator. The OP is not off in his theory and if it saves him actual money so he can ride his bike more more power to him. Who am I to judge.

 

It makes sense to me. I'm just curious is the OP could have a bad thermostat or if the unit is operating as designed. The more I think about it Harley probably wasn't too concerned about cold weather performance because such a low percentage of miles are done in those conditions.

 

that and being an air cooled engine I doubt it's freezing to death and needs to wear a parka

 

Being air cooled is actually more the reason to do what you can to keep the engine temps up. It has no internal way to maintain engine temp...

So yeah, sure running the engine cold won't kill it but it sure will suck down the gas etc and etc which was the OP's point.

 

Werd!