what size car tire can i use on my 2004 harley davidson ultra classic
 

what size car tire can I use on my 2004 harley davidson ultra classic

WHY???? Why in the world would you do that???

Car tires are built specifically for cars.

Bike tires are built specifically for the style of bike and the correct load rating.

Don't put a car tire on your bike.

Also, I have zero idea what size it would be?

Welcome to the site.

search "Darkside"

Here's the database, and source of all information: https://darkside.nwff.info/?p=tires

I don't know why people do that but to each there own. Try going to the Dark side section of this forum.

Looks like there arent too many choices for darksiding on a pre-2009. A narrow rim combined with limited fender clearance is what is stopping. The one option appears to be more expensive than most of the proper bike tires (Austone 175/16), and has really only been done with sidecar rigs according to the site listed above. I know that even with dedicated bike tires, we can only go with up to a 140 width tire (up from the stock 130) due to clearances (or lack thereof).

I fit a 150 Avon on my '03 Road King, without it rubbing. That is as big as you can go.