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RX400h

Food For Thought

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Most us agree that engine oil needs to reach a certain temperature in order to "burn off" moisture that tends to make its way into oil. Typically, a temperature north of 180F is essential and that is why frequent short trips are sure to drastically decrease oil life.

Full hybrids like the Prius and RX400h may travel many miles with engine off during high-traffic conditions which, one would think, would tend to allow the engine oil to cool down. Let's say you commute 15-20 miles one-way on your way to work every morning and that there tends to be fairly heavy traffic along the way.

How would you suppose the hybrid would handle keeping the oil hot? If the oil does NOT remain hot or if it never reaches a high enough temperature to burn off moisture, wouldn't it be prudent for Toyota/Lexus to incorporate an oil life monitor that adjusts oil life accordingly?

Does anyone know how this type of situation is dealt with? I may have to change oil more frequently if I see that the oil temp cannot get beyond 180 or so.

Comments?

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Nowadays with the engines more thoroughly sealed against escaping emissions vapors and no breather cap/path does the crankcase still accumulate all that much moisture?

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Nope, just regular oil.  I spoke to the dealer & the recommended oil change interval on the hybrid will be the same as their other models at 5,000 miles.

....thus, the quandry I bring up! How will the oil remain hot enough to burn off moisture? A coworker bought a 4-Runner back a while ago and drove it to work every day. The trouble was that he lived only 3 miles away. By the time the engine had 50,000 miles on it, the oil sludge caused it to fail totaly. His engine oil never reached "operating" temperature, either to or from work. Why would this NOT happen in a hybrid that shuts its engine down at low speeds, in an environment that encourages on-off cycles that are spread apart significantly?

Maybe SW can elaborate since he has a Prius?

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They've talked about this on the Prius boards a lot, if you want to check them out www.priuschat.com is the best one. Lots of gurus on there that have done oil analyses and things like that. Our Prius only gets about 500 miles a month put on it so we change the oil every 4-5 months or so. The oil stays good and clean, much cleaner than the oil on my ES which gets really nasty really quick (I use full synthetic on both cars). I believe the engine is designed to reach operating temperature really quickly.

wwest has a Prius too, I think his is the older model though.

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A coworker bought a 4-Runner back a while ago and drove it to work every day. The trouble was that he lived only 3 miles away. By the time the engine had 50,000 miles on it, the oil sludge caused it to fail totaly.

The owners manual of your friends 4runner recommends oil changes every 6 months / 3,750

miles if the vehicle is used for short trip service. Your friend very likely did not change the oil that frequently and that's why it sludged.

Given that it only costs $12 total for 4 quarts of motor oil and and a Toyota oil filter, I do not undertand why so many owners agonize and fuss over oil change frequency when just following the old 3 month / 3,000 mile rule would provide peace of mind against any engineering deficiency or stressful driving habits The 3 month / 3,000 mile rule costs a do-it-yourself owner just $48 a year in oil and filters.

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They've talked about this on the Prius boards a lot, if you want to check them out www.priuschat.com is the best one. Lots of gurus on there that have done oil analyses and things like that. Our Prius only gets about 500 miles a month put on it so we change the oil every 4-5 months or so. The oil stays good and clean, much cleaner than the oil on my ES which gets really nasty really quick (I use full synthetic on both cars). I believe the engine is designed to reach operating temperature really quickly.

wwest has a Prius too, I think his is the older model though.

I will check out that chat forum - thanks!

VGR, I have no qualms about changing oil early if needed. However, I am curious as to how Toyota tackles this issue. I drive my Corvette 8-9 miles to work almost every day and the oil temp (I keep that readout displayed on the digital info gage) shows that during the Winter months, the temp gets up to about 180F. It can get as high as 200 during the Summer, but I have to wonder how low it would be if I lived in a colder state.

Dave

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They've talked about this on the Prius boards a lot, if you want to check them out www.priuschat.com is the best one. Lots of gurus on there that have done oil analyses and things like that. Our Prius only gets about 500 miles a month put on it so we change the oil every 4-5 months or so. The oil stays good and clean, much cleaner than the oil on my ES which gets really nasty really quick (I use full synthetic on both cars). I believe the engine is designed to reach operating temperature really quickly.

wwest has a Prius too, I think his is the older model though.

I will check out that chat forum - thanks!

VGR, I have no qualms about changing oil early if needed. However, I am curious as to how Toyota tackles this issue. I drive my Corvette 8-9 miles to work almost every day and the oil temp (I keep that readout displayed on the digital info gage) shows that during the Winter months, the temp gets up to about 180F. It can get as high as 200 during the Summer, but I have to wonder how low it would be if I lived in a colder state.

Dave

I use MOBIL 1 in all my vehicles, after breakin, my machanic says that my 135000 mile minivan's engine looks like new

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