Quick Purchase Question from a Noob

Welcome to PriusChat & Congrats on the two new Prii. I also received my Prius on a dealer trade. I would not worry about. I have had no problems. As mentioned in a previous post you MPG willl go up as time passes.

 

It's probably fine, but this implies that you have not read the owner's manual very closely. You really should do that. There's more info in it than you can get from reading this forum or than can be discovered by experimenting with the car. Also read and follow the scheduled maintenance guide. It will save you money and bother.

 

US oil standards are lower than those in Europe and Japan, thus poorer quality oil is most commonly used by dealers and quickie places. I use Mobil 1 but at the 6 month/5,000 miles interval because I don't want any chance of arguing with Toyota should some related warranty repair ever be needed.

 

I still find it amazing that you have to change your oil so often, mine just had its first service at 10,000 miles. Surly our oil is not that much different?

 

From what I read about breakin on Johns site John's Stuff - Toyota Prius and more was to drive the first 600 miles at 65 or under and cruise control was fine for open road. After that it is broken in.

 

Actually, yes, our oil IS that much different.
The certification testing is much less stringent, and commonly available oils (bargain oils, or what's in the barrels at the quicky oil change places) tend to have widely different sludge points. The level of impurities allowed is different, too.

 

evening folks,
gary here from boston area. just picked up my new prius on wed. barcelona red with bisque int... im am getting about 53mpg so far.. i was talking to a tech, and he advised me to use mobil 1.. he says it will improve you mpg,and better for the engine, and i should change to it within the first 1000 miles... i have to say what a great fun car to drive.. i also drive a s430 and a sl500, and i have more enjoyment in the prius... i told my wife that in the fall i think one of the s430 might be history!!!! i guess its like been there and done that..... later from bean-town
gary

 

The service manager told me when I bought my first 2004 Prius that I should vary my speed for the first several hundred miles, that keeps the rings from scratching the cylinders staying in one spot a long time while breaking in.

I recalled from a few years ago that when a truck we had recently installed a new motor in and now had about 500 miles on it and used only at one business location (no road travel) it started smoking, some. I complained to our mechanic. He explained that the rings which are staggered on installation will work around to being lined up allowing oil to get pasted causing it to smoke, so varying the speed may have something to do with that. I had noticed many other working trucks in salvage yards that smoked. I had wondered why peolpe using these truck so much in their business did not fix them. So his explaination finally made some sense.

I also recall when my mother died several years ago, she had a one owner 67 Mercury with very low mileage. I think about 30,000 miles. It was 10-12 years old. I know she had the oil changed every 3000 miles or less and never drove over 55 mph, and most of the miles in town at slow mph. I received the car like new, but it also smoked, some.

When I bought my 2007 Prius there was no mention about breaking in speed.

 

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I have a personal opinion that varies from some conventional thought on break-in and I would like to make some points to ponder, if you will just pardon me.

I don't think it actually makes much difference if an engine is run any differently during break-in than normal driving. From a logical standpoint, I have never read any real evidence of exactly what difference this would make. In other words I think that break-in fear is an illogically based assumption even though it is common.

There is a very short time when a new engine is first started that some little protrusion or leftover grit may exist in a cylinder bore or bearing surface but this highly unlikely considering the clean conditions that are specified during assembly. Even if some slight defect could escape fine honing, polishing and cleaning, the huge amount of cycles that parts pass each other within the first couple of minutes would flatten, and/or flush, just about anything.

The overall fit of parts (the clearances) are either correct to start with ...or incorrect and no intermediate amount of "break-in" wear will improve them. Parts that are too tight will overheat very quickly and be forever ruined. Once an engine is brought up to maximum temperature and not seized or damaged, it's good for the duration. Parts that are too loose will always be loose.

One can consider the building and testing of racing engines that are often assembled, run for an initial 5 minutes warm-up and then run hard, loaded at full throttle on a dyno. Some of these engines are crated and delivered immediately. The recorded power is sometimes included on a card with the product. No conventional break-in.

I don't think that even allowing the gaps to line up on a set of rings would be all that bad. But it does seem intuitive to not do it. But think about it. If combustion gas is going to leak straight up through the lined up gaps, why wouldn't it leak in a zig-zag fashion out the same gaps at about the same rate?

Some combustion gas does leak, of course, but proper sized gaps minimize this until ring wear opens them beyond acceptable. There are gap-less rings available, but apparently they are not all that necessary. Perhaps if the gaps were lined up, the cylinder wall would have a single vertical ridge began to form where there was no wear because the tiny gaps all missed rubbing this same line. So what? Wouldn't this ridge somewhat fill the gaps left by the ring and wouldn't that actually theoretically improve the seal? I stagger them because it cost nothing but I can't see where it has to be that way.

From my observation, I think that poor ring seals occur because some engines are chronically run at too slow of speed or nearly idle. At slow speed all normal engines won't run right without rather rich fuel mixtures because they simply aren't efficient at under designed rpms. Partly cam timing, partly poor mixing and distribution, partly low compression (remember closed-throttle idle causes an engine to, at best, compress a partial vacuum). Carburators were the worst but the "richness" problem still exists with the best fuel injection systems, one of the reasons the Prius engine avoids idle. Direct injection (into the combustion chamber) may help since fuel can be directed at the sparkplug because plugs won't easily fire a lean mix. A vacuum (idle) has wider fuel molecule spacing by nature, right from the get-go.

Rich mixtures produce dirty burn particulates and raw fuel washes cylinder walls and wear goes up accordingly. A burned gallon of gas produces more than a gallon of water and a bit of it ends up in the crankcase from leaky combustion. Think about how much condensation runs out the cold tailpipe; the hydrogen (H2O) therein was all once part of the hydrocarbon fuel. The engine may not warm enough to evaporate this poison. It used to be worse when there was more sulfur in American fuel and oil. Water and reactive sulphur oxides produce sulfuric acid. Acid rain in your engine.

Another bad thing for engines is not being run at all for extended periods. Some cylinder walls actually can slightly haze as they began to rust inside a dormant engine. Cold cast iron attracts humidity as the day warms up, even inside an engine. The slight corrosion is scraped off the walls by the piston rings and tends to gum them up, along with particulates, causing them to sometimes stick in their piston grooves instead of a proper tension seal against the walls. Oil eventually drains from surfaces and bearings. Corrosion and dry starts are common.

I think a good break-in is to drive a new car like you would normally. Any hard driving will shorten the life of the engine whenever it happens.

My opinion anyway. Thanks for listening, guys.


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I think you got smoked.
The reason a re-ringed engine will smoke if not run in properly is the rings need high pressure behind them to push them out into the bores so the rings and honed bores wear against each other. If an engine is let idle too much the bores can become glazed(shiny) which allows the oil to get past the oil control rings. The rings will not turn on the piston and there is no magical force that aligns the gaps, really.

If a repair shop beds the rings in properly after an overhaul the engine shouldn't smoke any time soon.