I do keep tabs on my fuel mileage at every fueling, and has been doing that forever. For me is a simple way of knowing if something is not right. The numbers I currently have are since I moved to the States 14 years ago. In that time I have driven 20,000 miles. For the first 3 years I had the original type carburetor, the Hitachi VC42, and then I switched to the Carter YFA. The numbers came as a surprise to me, since I thought that the Hitachi was more fuel efficient. Bear in mind that my driving is normally 10 miles of light traffic streets where I don't even have to brake, and 10 miles on a 50mph highway. These numbers are not offroad.
Carburetor | MPG | L/100km |
Hitachi VC42 | 12.75 | 18.4 |
Carter YFA | 13.79 | 17.04 |
The Carter YFA gives the engine a little bit more power and it can easily rev to 3800rpms, I used to have the Hitachi VHA carburetor (Patrols from 69 and up) and performance was on par with the Carter YFA, but at a lesser fuel economy.