Tell me why I can't change my oil every 10k?

Nothing's stopping you. Go right ahead. You might have problems with the warranty, but only if they could prove you didn't follow the recommendation.

 

<div class='quotetop'>QUOTE(sl7vk @ Nov 1 2006, 06:20 PM) [snapback]342317[/snapback]</div>

Warranty coverage.

 

<div class='quotetop'>QUOTE(sl7vk @ Nov 1 2006, 09:20 PM) [snapback]342317[/snapback]</div>

Nobody is gonna make you change your oil. I doubt that you'd see any problems before the warranty expires, but seriously, changing it yourself even using Mobil 1 and a dealer filter, you're only saving $25 a whack, versus the nagging feeling that you may be taking life off your engine. If you're worried about costs, change it every 5K and use regular oil. What's your peace of mind worth?

 

well- if your oil sludges they know it's not a defect in the engine design. the cause would be lack of oil changes. [edit: prius engines are NOT prone to sludging, a sludged prius engine will automatically raise eyebrows]

if you wanna take the chance, go for it. you may be able to fool them. most likely, damage won't be evident till the powertrain warranty is expired.

DH has a sludged highlander engine on his bench with 62k on the clock- 2k out of powertrain warranty. the oil wasn't changed often enough. engine's dead, needs to be rebuilt from top to bottom. they have "receipts", but toyota's not going to cover it and the extended warranty company knows they're full of it. complete consensus is lack of oil changes- the evidence is there. even under powertrain warranty, you'd have a very difficult time convincing toyota to rebuild your prius engine.

other effects known from inadequate oil changes include piston wear, ring wear, cylinder wear, bearing wear.

oil starts to oxidize and loses lubrication properties after a certain number of heating-cooling cycles. it's not in a sealed container away from air supply.

the choice is yours to make, don't count on toyota to take care of any problems. in fact, you can probably count on a alternately worded "screw off" or the like.

i think our stance on the matter is pretty clear after this post.

if you're buying the oil and filter anyway... why not put it in the car? protect your investment.

 

i think the point the original poster is making is that the european prius does have a 10k mile interval. if this is true, whats so different about the US one?

 

Keep in mind that oil also gets moisture and acids from combustion byproducts. The hybrid may be easier on oil, which I'm not completely convinced of, but why skip oil changes, even for environmental reasons? It's not like I'm pouring the used oil into the wetlands, it gets collected and recycled, and compared to the gallons of gasoline that are burned, the 3.5 quarts per 5000 miles is trivial. And I always look at it in these terms too, in the bigger picture, if the car is junked sooner because an engine goes, then a lot more oil will be needed to make more cars than might have been needed otherwise.

 

well... to get picky the EU prius has a 9k mile interval.

anyway, DH's 1989 camry has a 7500 mile oil change interval. which we'd be happy to do if we didn't actually need the car.

the prius has a high compression engine, and it circulates oil even when the engine isn't sparking so long as the crank is spinning. the crank is spinning quite a bit even when the engine's running. increasing compression ratio increases output force from each cylinder, transferring more force into the piston, connecting rod, crank than the standard 1nzfe. this makes the oil work harder.

the only reason that the engine can have such amazingly tight clearances is because the oil fits in there and separates the metal. after 10k or so the oil tends to thicken. the shear point decreases more easily, which means the oil can be pushed out of the way so to speak and metal can contact metal.

there are a lot of people who are attempting to push their oil life. DH has had to deal with many of them. in most cases, engine damage has already happened before he sees the car. the entire point of all this typing is that you can go ahead and try it if you like. if (er, when?) damage results you're going to be stuck with it, no passing it off on toyota. they know about sludge from engine design now, they're not going back there. you made a sizable investment in your car. why risk damage from something so simple as an oil change? why not risk it on something more fun like a prius hack?

 

whoa. calm down there. no need for hostility.

DH is a technician at a toyota dealer. OUR stance = his stance and i back him up.

 

<div class='quotetop'>QUOTE(sl7vk @ Nov 1 2006, 11:08 PM) [snapback]342373[/snapback]</div>

As I said before, no one is forcing you to change your oil.

I follow the schedule, since in my case it's probably cheaper and easier than getting an oil analysis, and I always plan on keeping a car 10 or 12 years or longer, and the cost of oil change are trivial compared to say, the insurance bill for a given year. Not sure why you only changed it every 10K in Chamonix, different spec engine? Different warranty? Why do you think it was different?

As for protecting their service centers, I don't think most people don't go to dealers for their service, most of my "car guy" friends DIY, including myself. The folks that aren't tend to get into a Jiffy Lube or other system where they end up with 3K/3mo oil changes, or they change it once a year "whether it needs or not." As I said before, I doubt you'd see any problems before the warranty expired, but I'd feel like I was potentially reducing the life of the engine. I don't really feel like I'm arguing, you started the topic here, and folks are just giving you their opinion. Just trying to be helpful.

 

sure there's no design difference in the engine. there's no explanation for the difference in requirement for warranty service, but here the interval is 5k if you want warranty coverage. arbitrary or not, noone can change that but toyota.

noone's calling you a moron... as far as i know facts and educated opinions can't be construed as a bitchslap unless you want them to. you wanted to know why this wouldn't fool toyota. that's what we addressed: there's plenty of evidence when sludge is caused by too-long oil change intervals.

your car will probably be okay. just know toyota likely won't be fooled, which is what you asked to begin with. so long as you understand that you can't expect warranty coverage should something go wrong here. we offer our sincere apology if we made you feel like a moron in the process, there was no intention to do so.