Can you advise the source for the nipples?
I converted a mower years ago. I used the valve on the 1 lb tank to adjust the rpms. Does the regulator work better for this purpose?
G-d gave you lots of talent and completely missed me. When I first saw it I thought it was the Col Reb from Ole Miss.
I think less resizing of the hoops would have been necessary if the barrel could have been soaked in water. The staves dry out and shrink. Of course that may have been a difficult thing to accomplish. Once it started to expand you might have been able to fill the barrel with water. I had a similar issue with a whiskey barrel half used as a planter.
I do remember reading to my surprise that better MPG is realized with a solid truck tailgate in the up position. It counter intuitive but seems the air going over the cab hits the tailgate and creates a bubble that allows the air to flow over the bed altogether. Interesting article.
You might try this type of configuration for the tailgate. The truck lines have found it to save fuel. I would resist running tires at maximum sidewall. It might save fuel but it's horrible on the life of the tires. Safety can be an issue since the traction and stopping ability is severely downgraded at maximum pressure. These pressures are for extreme loads. You might try the chalk test to determine maximum pressure while maintaining a maximum contact patch.
Kids change priorities. Does Bio Diesel cost more that regular diesel? It's an old trick the car dealers use to do and I suppose still do where they would under-inflate to make the vehicle ride better. They do make vehicle tires that are harder compound thus less friction and in effect translate to better MPG. I have some experience (LOL) in ruining a few tires.
My pic didn't come out right this site has the entire thing. https://www.autorepairboulder.com/why-is-tire-infl...
My mower is front drive and I was worried the screws wouldn't be enough so I used contact cement and screws. I was concerned when sideways pressure was applied the tread would slip off. Mowed today with it and worked fine.