Warranty question, what if on the outside chance something goes wrong with your motor and you didn't follow Toyota's recommended oil change intervals of 5K or 6 months? Toyota will wiggle out of a warranty claim if they can.
That's a good question
Let's suppose there is a hidden manufacturing defect somewhere, say a hairline crack in a connecting rod that made it past routine inspection. You're driving along and BANG steam and oil are all over the place.
In that case, let's also suppose you were running Amsoil and changing the oil and filter every 12 months. With a hidden defect, you could change the oil and filter every Saturday morning and that wouldn't prevent the failure. Could Toyota wiggle out of a warranty repair? Sure, I guess
Or, how about the sludge issue that Toyota had to cough up in that class action? I wonder how many of those motors had the 7.5 K interval done at Toyota dealerships, running crap min-spec bulk dealership oil?
When my Prius was about half a year old, I had already gone through the 2 free oil changes at the dealership. Switched to Mobil 1, ran it 10,000 km, changed it and had it sampled. Had *alarming* levels of sodium, sulfur, and nitration
Presented this to the dealership and Toyota Canada. TC came back with a snotty letter stating my use of Mobil 1 was to blame, hinting my warranty might be voided. I contacted Mobil and they stepped up to bat for me
We chased a lot of dead ends. The next oil change, results were *better* not worse. Matter of fact, 2 oil changes of Mobil 1 later, lab results were still getting *better*
The Mobil engineer assigned to my case then suggested I try to obtain a sample of the oil used previously. Duh, I should have thought of that. Dealership had no problem with this, I guess they assumed all motor oil was exactly the same, especialy the bulk stuff sitting in the tote bin outside with TC's approval
That stuff was s***, I wouldn't run it in a 20 year old lawnmower: contaminated with free moisture and dust, high sodium, high sulfur, high iron, etc. A 3,000 mile interval was probably pushing it with that garbage
The tote bin should have had a desiccant breather, instead just an inverted pipe with a screen. That explained the dirt and moisture, the rest was just crap no-name low-bid-of-the-month oil
In the meantime, TC was still acting pretty smart, suggesting my engine was toast and it was *my* fault
So Mobil - armed with this damning evidence - contacted Toyota Canada. Very quickly, they STFU.
So if I had had a problem with my Prius motor, probably barely off warranty, TC would have laughed at me for using a non-recommended viscosity and interval. When the garbage sitting in the dealership tote bin was probably to blame