Hmmmm....
Primary drive is through "tourqe converter". Lowering final gear ratio will increase load on engine. I would think the "slightly" higher RPM (by adjusting govenor) at top speed would be "easier" on the engine.

I also investigated gears recently and ended up agreeing with several others on this thread. With wheels, a going theory is you can add about 1mph for each additional inch of diameter on wheels. I have a 2021 Drive 2 QuietTech fleet vehicle and tied the governor open. Using my GPS speedometer as the reference I went from about 22 mph wide open to, on average, 24 mph and hit 25 often depending on how the wind's blowing. Highest recorded speed has been 27 mph. So for the cost of a tiewrap vs $300 - $500, I've increased buggie speed by 3 - 5 mph. No changes in tires either. That's just my personal experience.

Ask your friendly sheriff’s deputy about the cost of operating an unlicensed and improperly equipped low speed vehicle. Separate tickets for no wipers, no hydraulic brakes, improper wheels and tires, etc etc, and of course no insurance.

I have the 2022 Quiet Tech PTV. It has the "high speed gear" set. We have 10" wheels with 205/65-10 tires. These are 20 inch diameter and the cart goes 20mph. I am not a golfer and we use the cart for transportation only.

The Fleet carts are made for the golf course and top out at 13-15 mph. So when the OP is looking at the high speed gears it is certainly not going to make the cart a speed demon.

An hey, if you want to spend you money on the gears, do it. Other folks here might choose to spend $500 on painting team murals on their cart. Or others may add speakers or a hard enclosure. It's your money do as you want.

I've had this done on my fleet 2019 Yamaha. If you increase the governed speed and run it too long if will damage the governor. I got mine up too 19 mph but the rpm's were so high the rear end pressure relief hose was constantly leaking fluid. If you want the new gear installed dm me and I will send you the local guy I used. Good luck.

The Villages Discount Golf Carts...

I highly doubt that due to all Yamaha gas carts flying by me with golf clubs on back. I would check transaxle gear oil level it might be over filled?

There is a difference between "Fleet" Yamaha carts and their "PTV" carts...

The "Fleet" carts don't have the "High Speed Gears" and are designed to only top out at abut 15 mph. Very few of them are sold in TV...

I completely don't UNDERSTAND why The Villages does NOT Police the golf carts speed enough so that everyone is doing around 15 MPH. Allowing some people to have faster golf carts is just asking for EXCESSIVE passing and therefore ACCIDENTS. We are all retired here........what is the hurry.........some people get to the swimming pool faster so that they get more suntan and skin cancer. They end up walking sideways in the pool anyway.
......... Golf carts have high centers of gravity (maybe not the E-carts) and when you increase their top speed you increase the likelihood of a rollover. They are designed to go SLOW on purpose.

Yes, after a rollover when someone is hurt or knocked out, they will while unconscious, cut that zip tie. What a great plan (so devious) to be able to brag that they go 5 MPH faster than someone else. I think that I would use my time and brain cells in more productive activity. Go work at a charity.

When you drop the RPMs in a gas cart (or any vehicle) you get into the lower part of the torque curve and the engine likely will labor from rest up to speed. That will make the engine less reliable over time.

I agree, but I would NOT waste my time doing either one. I would rather use my time fishing or doing something equally boring like playing golf.

I wish that the Police or cameras could give out tickets to control all excessive speeding in a golf cart or in a regular automobile. Suppose a speeding golf car rolls over (they do that a LOT) and hits some member of your family?

That would be fine if a rollover or other accident does NOT affect other people. It will cost society money for an ambulance and clog up the hospital unnecessarily.

Will there ever be a time that stating your opinion just once will be enough? Being a broken record isn't going to make people listen to you. It's just going to make them ignore you even more than they already do.