If you was referring to me it was more of a curiosity type question . If you look back at my original post you will see I said I don't care about mpg and hadn't really given it a thought till I checked it just to see if it had changed with the cam upgrade. I didn't do the upgrade looking for gas mileage. Just new to Harleys and still learning what is the norm and what isn't .

 

No. actually I'm not. I do however see quite a few post on the topic of mileage depression after an upgrade, I have been a street rodder for many years, built a few motors in my time and am familiar with the decrease of mpg and increase of hp, thats all...

 

How did your 555s do for power and tq. Should be a nice little bump of useable tq.

 

They are all they are cracked up to be in the low/mid rpm range . Not sure how to post a pic of my dyno results but I went from 72 hp to 88.5 and torque went from around 90 to 110 lbs if I remember correct . I'm over 100 ft lbs of torque from about 2300rpm up to about 5000. Those numbers may be off a tiny but as I don't have me dyno sheet in front of me but they are close .

 

I'm right there with ya. Stock motor except for a mild cam, after market exhaust and hi-flo AC. 39/40.

 

Would it stand to reason that the hotter the cam, the less fuel eficiency?

For example, would a Woods TW-222 be more fuel efficient over a Woods TW-555?

Would an Andrews 48 be more fuel efficient than an Andrews 57?

Etc.........

Not that any of this really matters, but ........ curious.

 

Back to: more cam=more air&fuel=lower mileage, with all other things being equal.

 

I get about 45+ on a trip with my Andrews 48h in an 08 SG and a lot less in town cause I'm on the throttle a lot from light to light. A little under 90hp and a little over 100tq. No head work just s&s power tune duals A/C and thundercone mufflers.

 

Cam swaps and engine upgrades are a double edged sword when it comes to Fuel efficiency. Yes as you go bigger the motor does require more fuel,,, but with that same effect it is also much more efficient in the power it puts out with less throttle applied.

So if you build for torque and match your gearing if you are cruising you can still pull very good mileage ( less throttle needed to get bike in motion)

but if you are building the motor and applying bigger cams,, There is a very good chance you are going to snap that throttle and twist it farther,, which will make you burn more fuel.

I could fluctuate my fuel economy from 26 MPG to 42 MPG all in how hard I was in the throttle.