I have an 04 Heritage Softail Classic and had my 1K service a couple of weeks ago and had the dealer put synthetic oil in the motorcycle and the mpg went from 42 mpg to 48. I checked it in two tank fulls and it has been virtually the same, 48 miles per gallon. I don't think it is related to an instant breakin or anything. I can't tell if I have any more power or not because I don't hot rod or anything but I think I must have more power to get that much of a gain in mpg, 12.5%. Has anyone else experienced this.

 

The synthetic will improve gas mileage as will break in. I can't say that I've experienced it though because I don't really pay attention to gas mileage much.

 

I always check mine. I like to keep up on it because it is usually the first indication that something is not going right.

 

Please, don't think that your getting better gas mileage just because you changed over to synthetic oil[sm=forgetit.gif]
I think that the increase will be so mynute, that you will never notice it but if you sleep better at night, who am I to say other wise

 

what would you atribute it to?

 

Hi, new poster here, '04 Heritage also. When I switched to synthetic my mileage also went up a couple MPG but not as much as yours. I can tell the engine ran better.

 

I have noticed an increase in mpg with the synthetic oil. Just got the highest ever with a tank at 42mpg and working on pretty close to the same with this tank. Bike has almost 7000 kms on it.

 

When I was a kid, I was told there were three things you did not talk about in polite company: sex, religion and politics.

As I got older and started hanging out with the "motorhead" crowd, I learned the fourth item not to discuss was motor oil, as the topic would quickly become volatile and overweight middle-aged men would soon start throwing punches and rolling about on the ground over the subject!

With that said, I have always "broken in" my iron on dino, switching to syn at the 1000 mile mark.

My Jeep has syn in both axles, tranfer case, tranny and engine and I get about 1 - 1 1/2 mpg more than my neighbor who has a Wrangler with exactly the same drivetrain, same size tires. After about a year or so, he finally submitted to the "dark side' as he calls it, and guess what? Yeah, I don't say anything when we're doing oil changes together....

I run syn in all three holes in my stock '06 FLHT and typically get right at 50 mpg at around 60 mph, around 45 mpg at about 70, riding solo.

But that's just me....

Bob

 

I get 1 mpg better in my Chevy Suburban with syn and 3 mpg better in my TC88 with syn.

 

Oil sure seems to be a sensitive subject around here but here goes. I also switched to synthetic at my 1st oil change in my 06 sporty 1200 custom. I to experienced better fuel mileage with the syn oil around 4 to 6 mpg. I switched mainly because I paid a lot of hard earned money ( as we all have) and it seemed like cheap "insurance" against early engine failure.
I run amsoil 20w-50 and mobil 1 gear oil in the tranny. If I can keep from upgrading to a big twin I'll ride this sporty a long time