Just daydreaming here but if you wanted to run E10 petrol in a Patrol what engine would you use? What modern engine can cope with that and still produce the sort of power and torque needed for average 4x4 duties?
OK. if you have done relevant modifications to the fuel lines, pump and any other perishables to suit ethanol then most efi cars if tuned to suit will run E10 and E85 any day of the week. running dual maps works well when E10/E85 is not available.
Condensation inside the engine is a huge challenge. I have tuned alot of 400-500hp 4cyl and 800+hp forced induction engine and all of them are up for serious maintenance around the 35-40K mark.
Valve seats, Bearings and serious engine sludging are the main reason. Generally running serious water/oil seperation systems for any type of long term use along with very expensive valve seats is required for a road going car using it as a daily fuel.
Being putted around town with little to no heat buildup is the biggest killer to be honest. With e85 there is about 30% more fuel going into the cylinder than ULP so the cooling effect it has is dramatic, much like a methanol powered drag car not even needing a cooling system due to the amount of fuel being used.
Oil dilution is what IMO kills the bearings. I have had 500hp forged 4cyl engines do around 3000km on E85. Forged pistons and the likes means alot of fuel gets pased the rings when it is cold.
On one daily driven Subrau we drained 7lt of oil out of the 5lt sump after not even 3K km's. Once the oil analysis came back the routine changes were dropped from 3K down to about 1200km to even get the thing on the scale of normal for an engine.
That motor was completely torn down after about 50K km of serious abuse. It was running on 2 cylinders out of 4. Bottom end was pristine! Valve seats.... 1 had a near 10mm gash out of the head due to blow by. So the extremely short duration the oil stayed in the engine fixed the bearing failure problems, but the valve seats still suffered massive damage in a short period of time.
Basically all I am saying is more research is needed before jumping on the band wagon for a daily driven car.
I don't know anyone who has suffered as bad side effects as that from high ethanol fuel. One side effect we have seen on a regular basis is the gumming up of injectors in high boost situations (30+ psi). Mind you most of us on e85 test the fuel before filling up.
Example of some injectors caught before it caused any damage. This is from an evo after 2000km.