The MZ 6 cylinder was known as the sludger. The GR Series (found in all 2IS models, except for IS-F) was developed to replace the sludge prone MZ series. I would expect that Toyota paid extra attention to making sure that the GR series would NOT be sludge prone. The curious thing about this is that the GR series is not included on the memo. I run 0W-30 M1 AFE in mine and I change it at 5K which seems to be a total waste. The engine has 45K and it is sparkling clean on the inside. I am switching to 10K intervals as soon as the warranty runs out.

As a side note, a friend of mine who has an 08 Accord with the K-Series 4 banger drives 90% highway miles and the service indicator has him going close to 10K on non-synthetic oil. The engine also looks sparkling clean. The Toyota 5K interval seems to be beyond overkill to me.

 

I a happy to hear this because going in for service every 5k is annoying as hell

 

Straight to the point, and I think Lexus is well aware of it when comparing maintence intervals to it's premium rivals. My dealer is already allowing intervals up to 7500 miles with non-synth oil.

 

send your oil in for an analysis to find out how long your oil can really go

http://www.blackstone-labs.com/

 

So what is the oil change interval of the 2010 Prius in the US?

 

Call me old-fashioned and conservative, maybe, but I'd never go 7500 on dino oil and would only consider it with synthetic under the very best, ideal conditions.

 

"Old fashioned and conservative maybe" even when compared to my parents in their 80;s, but that's just a casual useless observation.

At least I didn't see maybe/maybe not in this thread.

But back on topic:

IMO, no problem with 10K intervals using Mobil 1 with my kind of driving. And what's the 2010 Prius interval at?

 

Seems to be a non-story to me. Toyota has been specifying 10k miles intervals on it's models worldwide for years. Lexus UK specify 10k intervals on on non-synthetic oil, Lexus Europe 15k kilometer intervals, again non-synth oil.

Audis and BMWs go 20k miles intervals on synthetic oils.

 

Who cares what your speculations are,

follow Toyota/ Lexus manuals on your respective vehicle.

Toyota spends Millions on studying oils and their behavior, id they say use

5-30w Every 5k then you do so. They Know best.

 

Yeah, you're definitely WAY over conservative. A few years back I sent a sample of Mobil 1 0W30 (I've since switched to Amsoil) in for analysis after 17,500 miles, and the report said to keep using it, because it was only a little over 50% broken down. That's right, it could have gone up to 30k without an issue.

 

I agree, oil have come a long way since a few decade ago. The lastest euro spec oil synthetic can easily do 15000 miles, most of the time its the filter that needs to be change, not the oil.

 

I agree. The mfgr designed, engineered and built the engine. Most importantly, they also provide the warranty. You can't go wrong by following their recommendations for oil changes. More frequent can't hurt anything, but probably not really necessary.

 

Euro spec motor oils have a lower sulpher & phosphorus content than non Euro spec oils. In addition, most european cars run hotter than their counterparts so the use of non Euro spec oil for extended periods can lead to issues down the road.

 

Okay, looking at this afar... what has changed really to say that instead of x miles to change oil, it goes to x+y miles, besides just printing the new miles? So yesterday 5W30 dino was only good until 3K, but today it's suddenly good to 5K or 10K?

 

The oil and the additives it contains have changed.