What does "reliability" mean to you?

No Time said:

In that extreme example, I'd say as long as the number of failures that occurred between change intervals was low enough (within total volume sold), then it would be considered reliable.

I would expect it to negatively impact sales, but that's a trade off the manufacturer needs to make.

Adding head gasket (transmission, chain tensioner, VVT cam sprockets, rod bearings, etc) replacement to the standard service interval would negatively impact sales because the customers would generally consider that less reliable overall... Which is why I also consider it part of the operational definition. When people say that preventatively replacing easy things is not a part of reliability but preventatively replacing harder things is, with some arbitrarily defined line in the sand separating them, to me that definition also lacks consistency.

The technical definition of a computer includes many things that most people do not specifically refer to as a 'computer' in typical conversation using the operational definition. If I say 'I bought a new computer', you can pretty well narrow down what general type of product I'm talking about.

Similarly, the average consumer does not know or ask about RAM (Reliability, Availability, Maintainability). In the absence of a word commonly defined and used as the combination of all three, the typical consumer considers all of that to simply fall under the 'reliability' umbrella. Give me a more appropriate single word that other people would understand in conversation, and I'll be more than happy to start using it.

P3PPY said:

Why must one perform "maintenance" other than that the part being "maintained" is no longer useful for its job? AKA the maintenance item is either broken or soon will be.

 

note to self:  don't buy a used car from P3PPY because he doesn't do oil changes.

P3PPY said:

Take this ten years into the future:

Might a prospective car buyer consider an EV more reliable than ICE because of the latter's regular habit of wanting oil, transmission fluid, belts, spark plugs, etc., and more regular brake changes? I think they might. And I wouldn't fault them. Because without that "routine" time in the shop, the car doesn't run. 

I'd say yes...............right until they have to buy a battery pack. Now if said pack goes 300K then EVs will absolutely be considered more reliable.

Paul_VR6 (Forum Supporter) said:

High reliability should not be confounded with low maintenance. They can go together but don't have to. 

Reliable is it does what it needs to when it needs to. We have an older Odyssey, with a lot of miles, and with a higher mile vehicle lots of things go sideways. What's amazing is that it rarely is something catastrophic where it can't be used. All sorts of things have worn out: door actuators, control and trailing arm bushings, wheel bearings, ball joints, brakes, tires, ac compressor, PS pump and hoses, alternator, battery, leaking valve cover gaskets, my latest evap issue (was the fn vacuum valve in the canister!), egr valve, drivers side window switches, two timing belts and waterpumps... that's just off the top of my head. Reliable? Definitely. Low maintenance? For almost 300k worth of use, maybe.

That's not my definition of reliable. Far far far from it. Just like I wouldn't call the Rio reliable. It's had failures that were odd and due to the way it was neglected. But they were still failures and caused problems. Wheel bearings that required knuckles, hubs and axles because of rust. Was down for a week waiting on parts. Knock sensor corrosion that allowed more knock to destroy a plug and coil. Cat's melting together because it burns oil at high rpm/load on track. It's previous life made it this way, sure but it's still not what I would call reliable. 

In reply to Driven5 :

I believe there is a cost and time aspect that comes into play when determining acceptable downtime and cost for maintenance. Those requirements gets taken into account in the design process and frequency of service required. 

A 30 minute service that costs less than $100 can probably happen quarterly without too much pushback from the market, but 2 days and $1000 would be unacceptable for many consumers. 

I know for many of the products I'm involved with designing there are requirement for time required for installation, time required for PM, and uptime. Design decisions are made to balance cost, time, and maintenance frequency. 

My position is somewhere between textbook reliability and durability.

Cars I care about reliability on are normally an appliance, and I consider their job to get me to work or wherever I need to go without worry. Most people nowadays think about cars as a luxury item and not a tool, so they care if their radio or sunroof goes out or something starts making a noise, I dont. I might get around to fixing those things but it will be a while. The modifier for me is when something fails how long can I ignore it without impacting the main function of the vehicle and how quickly can it be repaired.

My reliability gold standard is a TBI GMT400. The old saying was a small block will run badly longer than most things will run at all. Everything leaks, that fine I dont need much oil anyways. Oil pressure low, dont worry spec is only 9 psi at idle and Ill do just fine at 5 psi really. 13 psi of fuel pressure spec, ill run just as reliably at 7 psi. For 20 years I have seen these things neglected and abused by so many people and they just keep on going. The trans is the obvious weak link, but behind a stock engine (not enough power to hurt anything) Ive seen them go quite a long time, and at this point it is probably one of the cheapest transmissions to get repaired.

In reply to No Time :

Technically they would fall under 'availability' and 'maintainability'. But those aren't the words that the vast majority of consumers will use when comparing a car likely to suffer catastrophic failure whenever a 2-day $1000 service isn't religiously performed every 5k or less vs another only needing a 30-min $100 service every 5k-ish.

Technically they might both have the same reliability, but operationally I don't think customers would generally agree.