anybody have any input on these modules? i have the one WITH the o2 sensors. everything is ok and the bike runs fine, but my fuel mileage seems terrible. bikes an 02 nightrain fsxtbi with about 8500 miles. last time i checked i get about 30 mpg, ill be checking again this next tank fill up. is this way down or is that average for our bikes? its my first harley, love the bike to death but i've heard up's and down's for the thundermax module.

thanks in advance for any help/info.

 

I an running a T-Max w/autotune as well. I love it. Yes, the mileage did go down. Think about it - the OEM unit is running super lean, probably way lean of peak to pass EPA. T-Max (and others) enrichen the mixture big time. This cools the temps and now the mixture is rich of peak and a reasonable AFM. On my Dyna, I think I went from around 40 to low 30s around town. On a long freeway trip it goes back up to close to 40.

 

Been running thunder-max since 2007. Fuel mileage will be effected but there are also a few things you can do to help that by adjusting your afr pages in your cruise throttle range. There are a few videos on you tube that describe on how to adjust the AFR for better fuel mileage.

 

I have TMaxs on 4 of my HDs. Milage does go down because you are running a richer mixture as Davidwideglide06 mentioned, I am currently adjusting my AFR tables and milage is getting better. One more thing to consider is if your speedo is off a bit it will affect your MPG calculations.