It won't be a few cents because few cents/gal isn't going to get the behavior change that is the point of the tax. The fundamental issue here is that you need

It won't be a few cents because few cents/gal isn't going to get the behavior change that is the point of the tax. The fundamental issue here is that you need to take what a lot of people currently see as their best option (driving an ICE car) and make that sufficiently worse so that the next best option is the one tons of people choose. Anything that gets the behavior change will necessarily screw a lot of people.