I'm currently looking to buy a 2018 RX350L L/certified with over 50K and the carfax shows sketchy service internal data (over 20K miles between services). I figure since this is an L/certified car, oil changes had to be more frequent than that.

Well, each time the vehicle needs an oil change, the maintenance message appears and is typically reset after an oil change (assuming it wasn't reset without an oil change). That should be recorded in the computer.

Can that be seen in the computer each time it was reset? Shouldn't this be known by the certifier technician during his certification inspection?

 

Nothing beats a physical written receipt showing what work was done and when. Anything else is bogus.

 

I change my own oil every 5000-7500 miles and keep track of it on my written records but I often reset the reminder at other odd times just to get it off the screen. I wouldn't trust that as a reliable record of oil changes even if it was recorded on the computer.

I also wouldn't put any weight on it being a "certified car". In my opinion, that is just a marketing gimmick by the dealers unless it includes a future warranty. I would assume that you are buying a used car with an unknown driving history like any other used car.

 

I think (not sure tho) you can go on Lexus website, enter your VIN and be able to see whatever maintenance records they have on file for your car.

 

I wouldn't go by carfax for maintenance service.

 

Certified basically means it is bundled with extended warranty package and 4 maintenance services, And has over 50% of tires and brakes left.
It has nothing to do with how the car was serviced by the previous owner. Of course they wouldn't normally certify a really beat up junk, but it could've very well had 2 oil changes in the 50k and that wouldn't affect the certification.

But not every shop reports to carfax and so if the oil was changed by a small local place you wouldn't see it in the record.