Leave aside the debate as to whether or ot it’s right to give farmers a massive tax break not available to most other industries, the theory behind red diesel is that duty is not paid on fuel not (mainly) used on the roads.
A lot of petrol is not used on the roads, lawnmowers, cement mixers etc, the question occured to me while using some as a solvent.
A logging compnay for example would pay duty on the fuel for the chainsaw but not the tractor.
why?

Have you seen how much fuel a tractor uses? You could run a chainsaw for life on what something like a combine harvester uses in a day.

Maybe, but if you run a big landscape gardening business you will have a lot of big mowers. And hedgecutters. And strimmers. Etc.
I agree it will be less per unit, but it must be a big total for a large company.

tax break for farmers LOL – they are soo rolling in it.

My guess is it’s to make food cheap.

Red Diesel isn’t just used by farmers, but is also used in construction and maritime transport (where there is little to no need for petrol)!

Large mowers such as Ransome triple mowers and mini tractors are diesel so they could use red.

From wikipedia:

Red diesel can also be used in road vehicles which are registered as SORN with the DVLA provided they are only used on private land.

I never knew that.

Adding to mikewsmith’s point, a tractor or harvester could easily be using 30 litres per hour. A big (big!) tractor can use 90+ litres per hour.

😯

The requirements for storing petrol is great than for storing diesel so for one, you would not have a large amount of petrol in a tank in your yard.

Also as cynic-al says farming must produce cheap food. Without cheap food consumerist economies like ours would collapse.

Remember when it used to say “DERV” on garage forecourts?
As in Diesel engined road-going vehicles. Not seen that for years
When I were a lad my dad had a gert big tank of red diesel on the farm.
Good question re red petrol. There ought to be an equivalent really.
Edit: ah yes storage. Diesel a lot safer

I guess it’s just demand way back when it all started… inboard engine commercial boats and tractors use diesel.

Where I work we’re using about 13,500 litres of red a Day! 😯

and that’s after some fairly significant fuel saving initiatives over recent years and we’re not busy at all at the moment 🙁

Petrol just wouldn’t be efficient for most types of heavy machinery

You can make a fuel duty reclaim though for use of unleaded if you use it for a qualifying purpose. Not that difficult to make an annual claim.

As said above – you need a licence to store petrol in bulk