1. With a rental you know the vehicle was serviced....with a privately owned vehicle you really dont
Do you think only rental agencies have service records? Private owners also have service records. And even if they put them in the trash, it's as easy as driving down to their servicing dealership and asking for a service history on the vehicle.
2. Many of the late model used vehicles on dealer lots are lease turn ins, and many people who lease may not use good gas, do the maint, drive it well, break it in properly, etc because they know the vehicle will be out of their hands long before any of the problems from the associated would crop up
That's exactly why so many companies offer "free" maintenance and oil changes on their leased vehicles. They found that people who leased for 2 or 3 years were neglecting the vehicles because they knew that they would not have them for the long run. Besides, comparing rental vehicles and leased vehicles is an apples and oranges comparison. Rental vehicles change "owners" constantly. Leased vehicles have the same "owner" for years.
3. Break in procedures on modern cars are not as big of a concern as they used to be and the vast majority of people do nothing special during the first hundred miles or so
Anyone should properly break in their vehicle if they want it to last, even with modern engine technology. Rental car drivers are much more unlikely to give a damn.
4. The 4Runners computer will not drivers over rev the engine or run it hard right after start up (which is why it shifts no higher than 3k rpms when cold)
I don't know what kind of special computer you have in your 4Runner, but the ones that I've seen do not limit rpms when cold. My BMW M3 has this feature, but not the 4Runner.
6. The best way to ascertain how a rental vehicle was treated is to inspect it for visual damage. If it is free of visual damage you can bet it wasnt abused all that much
Using visual damage is a poor way to gauge the condition of a rental car. For one thing, rental agencies have huge contracts with body shops to always keep their vehicles LOOKING new. Finding a rental that never had body work is like finding a needle in a haystack.
7. If someone pays to rent an SUV they are more than likely not your typical renter as insurance companies wouldnt typically pay for such a vehicle and most vacation goers who can afford to rent an SUV probably arent hot rodders.
There's nothing special about renting an SUV. Regular people do it all the time. The only difference is that people who more to rent an SUV usually need the utility it offers, so they rent it to tow a trailer, haul stuff on the inside, or to take it offroad--all things that are tough on the vehicle.
8. As far as the gas goes, I doubt very many renters go out of their way to buy bad gas. Many times they prepay the gas and return empty. If they do fill up I am sure they are pumping 87 octane in and that is what most owners will do, as this wont hurt the vehicle.
Of course they won't go out of their way to buy bad gas, but they won't go out of their way to buy good gas either. The cheapest gas they can find is usually what a rental car driving will use.
This is all I can think of right now. These vehicles still come with the balance of the manufacturers warranty.
