IS IT REALLY A LIFETIME OF A THING?

Toyota Canada, commencing in 2014 (at least that's when I noticed it crop up in the schedules), recommends brake fluid change every 3 years or 48K km's. The take away from flip-flops like this: it's mostly marketing, not engineering, that's driving at least some of the service intervals.

 

Used-oil analysis is a very interesting thing.

But statistically speaking it tells us nothing about CVT failures in the Prius. Evidence of actual failures appears to be fairly minimal, both on Prius Chat and on the web in general. What is needed is an analysis of the few transmissions that have failed, along with WHY they failed. Were there fluid changes? At what intervals? Etc.

Generally speaking, the necessity of gearbox oil changes comes down to two factors. What type of fluid is used, and what is that fluid expected to do? In the past, rear differentials and 3-speed manual transmissions represented the simplest of gearboxes. They were lubricated with motor oil or gear oil. Many of them lasted hundreds of thousands of miles on the factory fill. Either there was no factory replacement interval or it was ignored.

If I understand correctly, the CVT in a Prius is a fairly simple device, much simpler than in a gas-only CVT car. As such, it may be far less demanding on its fluid. The less a gearbox asks of its fluid, the longer it will last.

 

mine won't be there forever, only till it hits the salvage yard.

 

Let us start with the emphasized phrase. Toyota does not, to my knowledge "say" the HSD oil is "lifetime", they just do not have a service interval published for it. They do no have a replacement interval for most things, only inspection, like: belts, hoses, tires, brakes, etc.

Overall, the answer is that OEMs publish the maintenance guidelines for the "average" FIRST OWNER. Since most vehicles are only with the first owner <36m/50k, that is *really* all they are worried about.

Add to that the fact that most OEMs consider 10 years and 120,000 miles as the "useful life" of a vehicle, obviously there would be no value in providing recommendations beyond that (not that I agree with those numbers).

 

Can you cite a source for this, please?

 

Guessing @05PreeUs was referring to something like this :

Tier 2 : 40 CFR 86.1805-04 - Useful life. | US Law | LII / Legal Information Institute

Tier 3 (2017+) : U.S. EPA Tier 3 and California LEV III Rulemakings | MECA

 

Interesting stuff, SFO. The only thing I find surprising is that there's a legal definition for "useful life" of a car and that manufacturers don't design their cars to fall apart at 119,999.9 miles. They'd be clear of any liability because no car owner could reasonably expect any value past the "useful life".

 

Most consumers and lawyers have soiled the term "warranty". Warranty is really the manufacturer agreeing to repair an issue caused by a material or workmanship defect that occurs during the coverage period.

A defect is often conflated to imply a "material defect" and not the intended "defect in material". Any reputable manufacturer would gladly stand behind something they built where the material used (wire, terminal, casting, etc) had a defect (cut, bent, cracked, porous, etc) or their worker introduced a workmanship concern (loose, too tight, cross threaded, not connected, etc) to the product.

Such defects DO NOT include design limits, or engineering compromises. The fact that a HV battery does not last for 10, 20 or 50 years is not a DEFECT any more than the same would apply to a tire. Every part of a vehicle WILL WEAR OUT, you are using it up with every day and every mile put on it. Simply put, NOTHING lasts forever.

Comments are made all the time about this or that part that "should last longer". Sure, most things *can* be made to last longer, but at a cost. At some point, the product becomes so expensive that you cannot sell any, even if it lasts "forever". Lots of people make claims that they would pay extra for a better widget, when it comes time to plunk down the $$$$, things get real and the amount "extra" they are willing to pay is a very small percentage of the added cost.

The automotive sector has a very good database on how much their consumer base it willing to spend, the engineering challenge is how to get the "best" vehicle for that money. The consumer's perception of value may not match the engineering requirements; that does not make EITHER group wrong.

 

You obviously do not understand the term "design life". What is not in the links SFO posted at the "B" numbers (B10 for example), that really tell you how much life can be expected of a component.

Most OEMs aim for 0 defects in 36/36,000, an R/1000 of 1 or lower and a B50 life that matches design intent.

 

Not only that, but I don't understand the rest of your post, either!

 

Kind of off topic, but I think it's a bit enigmatic, nebulous for Toyota to say or use the term "Lifetime".
While I'm sure Toyota has done some application of projected usable lifetime of the vehicle vs. the durability of the fluid, and come away with the conclusion they can say "Lifetime", it does cause debate.

Plus with a machine should your really EVER say lifetime? Because what is the lifetime? Again, while there is a projected lifetime, or an average lifetime...with a machine? Those parameters can be changed.

Most of us of course reach a point even with a long, long term ownership where investment vs. buying something newer just works out that it's time for change.
BUT....

There are Model T's still, restored, maintained and perfectly driveable.

At this very site, I've witnessed owners that want to keep their Prius's as long as possible, what is their "lifetime" vs. The Average?

Why not if you are Toyota, simply pick a mileage or chronological marker, you could make it either a lot of miles or a lot of time. But just throw a number out there so owners aren't wondering what Toyota means by lifetime.

Because to me...lifetime is a moving target.

Since I think, all fluids will eventually break down and applicable protective properties decline, and I think the "Lifetime" of a vehicle can be a moving target...with the possibility of it being a much longer period of time than the "average".
Why not just abandon the usage of the term "Lifetime" and just give owners a guideline? Even if that guideline would become a period that for most would be well beyond either their ownership or probably the useful life of the vehicle.

 

I appreciate you likely meant that as a rhetorical question, but to answer it: maybe they're afraid to? It could be seen as a concession they went too far, saying to never change the fluid. And to change that policy now, anyone with a transaxle failure would go after them. And rightly so...

 

Unfortunately Toyota doesn't release that data of numbers and why the transaxle failed. All manufactures probably take this approach: proprietary information, that only the manufacture will see.

I can't see an independent shop spending time/money to investigate why a transaxle failed. They will just slap in a new or used transaxle, collect their money, and hopefully send the dead transaxle off to a metal recycler.

I am only aware of the strator being the most common source of transaxle fialures, based on Luscious Garage reporting and two postings about it here on PC.

I wonder if insurance people sit in the room along with engineering, marketing, and legal, when maintenance schedules are determined. All kinds of aspects are likely factored in. Failure rate of parts. Cost of doing maintenance on "A" and the increase in operating costs this produces, vs the probability of it failing, causing an accident/death, and the possible legal/financial liability this might expose the company to.

 

"Today’s vehicles are engineered to last 200,000 miles, but the U.S. Department of Transportation reports the average life of a vehicle to be 12 years. This number seems low for 200,000 miles, but it could be due to improper care and maintenance over the vehicle’s lifetime."

source: Fun Fact: Vehicle Life Expectancy 1930 and Now | Rad Air​

Chart of Average Age of Vehicles in US Household by US DOT (Department of Transportation).

Table 1-26: Average Age of Automobiles and Trucks in Operation in the United States | Bureau of Transportation Statistics​

 

The cost of a transaxle fluid change is peanuts, it's not difficult either.