Just a comment from a different perspective, with a a battery truck you are not buying your fuel costs up front. You must recharge the battery periodically and you need to add the cost of operating a charger to charge the battery and electric rates do go up periodically.
To project the cost of a recharge I have used this formula
take the kwH rating of the battery multiply it by 80% (the amount of power to be restored in an 80% discharged battery) increase that result by 10% (to account for power loss as the electricity runs thru the charger into the battery). This will give you a good estimate of the kwH that is used in a normal recharge. Multiple that times the customers charge from his power company. You will find that industrial rates are not the same from company to company - things likes total month usage can drive the rate (rates are negotiatable , except for residential folks).

On the fuel consumption of ICE engine. There is very little difference in the usage from one brand to the other as manufactures are using relatively the same size engine with close HP & torque rating curves for equivalent size models. This has been true for many decades. In fact ,the engines for many manufacturers are the same engine model & brand.(Nissan K21/K25 - in Nissan, Komatsu, Cat, Mitsu). Many years ago and on a planet far away, most lift truck companies used the Continental engine (Y112, F163, F227, etc). Certainly a company that had a decided fuel consumption rate would promote & advertise it in a quantitative manner rather than talk about it in loose terms like "for greater fuel efficency").
The only company that can prove a decided fuel consumption rate is Linde with their Hydrostatic drive axle & they promote it but you pay for it up front in acquisition costs.