'13 TWO Pre-Purchase & Found 5W30 Used - Abort Purchase?

Nothing at all wrong with using 5w30. Its one of the recommended viscosities for that engine. Toyota recommends the ultra-low viscosity in America only, and it’s purpose is to improve fuel economy.

It’s definitely arguable that 5w30 is a better choice, especially in the summer or hotter climates. But for sure it’s not a reason to pass on the car.

These cars are very reliable. Things can happen at 150,000+, but they’re nonetheless reliable.

In the Maintenance & Troubleshooting area of this Forum, you’ll find the NutzAboutBolts maintenance videos. The one I’d look at is the EGR Pipe cleaning. It’s very easy to remove this pipe (not the whole EGR). From there, you can look at how clogged the pipe is and make a decision. It’s probably never been cleaned, and there will be some deposits. If they’re hard but the pipe is still clear, I wouldn’t worry. But if they’re sooty — wet and greasy — and especially if the pipe is clogged, then I’d avoid the car.

There are a lot of maintenance procedures you can tackle yourself with a Prius that old, and you should, if you want it to last. It’s all in the NutsAboutBolts area.

 

I just meant that using synthetic oil should allow you to stretch the Oil Change Interval a little longer than with conventional oil, but there is still a limit to how long you should leave it in the crankcase. I myself am a confirmed believer in using synthetic oil to prolong engine life and conserve resources as much as possible, and I have been known to stretch OCI to something like 10k miles and 18 months, but now that I'm retired, most of the driving I do is confined to long cross country trips on the highway at moderate speeds, which I believe would allow for a longer OCI. Still, I have enough confidence in the durability of Toyota engines that I would not advise you to give up on this particular car, just because the OCI seems longer than usual, even if most of the trips it made were short.

 

Man oh man.....if I did oil changes based strictly on suggested time instead of miles? Some of my cars would have had the oil changed every 400 miles..........I have a 1995 K1500 that I've had a few years now that I haven't even put a thousand miles on.

 

I agree, miles or months falls apart at really low miles.

 

There are very few True synthetic oils, so don’t assume you can go 10k miles on a “Synthetic oil”

 

To the OP, I would say there is no way to totally divorce yourself of risk when buying a used vehicle.
But you've already done more due diligence than most just in noticing the situation and wondering what it might mean. Most people wouldn't even get that far.

I would say, maybe the concern shouldn't be so much about what Oil was used, or trying to sleuth out why, but simply what condition the engine is in today.
If you really want to minimize the risk, have an independent mechanic check the engine. Maybe a compression test.
If the engine passes, then what Oil you decide to use from today on....will be the decision, not a worry about what or why a particular weight was used in the past.