What oil do you use in your Prius?

You kinky girl, YOU!

 

Jen

Due to the server problems I haven't been able to login since Friday. I just sent you a PM

Hope you're getting better

To minimize issues with the dealership, use the 5W-30. No point getting into a long - and ultimately futile - debate with them over the fact the Prius in Europe specs a wide range of viscosity, or the difference between North American API specs and European ACEA specs: they'll just hear whaa whaaaa wha whaaaaaa like Charlie Brown's teacher

In summer temps, I've never noticed any difference in fuel economy running 0W-30, 5W-30, 0W-30, etc. A very minor difference - about 2 mpg less - running 15W-40 heavy duty oil in summer temps

The big difference is in winter

Remember that with engine friction, the effect on fuel economy isn't as dramatic as you might think. A maker of extremely large - the size of an average house - industrial V-16 engines, Waukesha, experimented with different piston rings and other changes.

Reducing engine friction 50% reduced fuel consumption 5%, but they had problems with oil consumption. That sort of motor would be used to run a +5 MW generator, a pipeline compressor station, etc. Those folks also care about fuel consumption

The primary reason I went to 0W-20, or 0W-30, for winter was the fact my temps can dip to -40. Even though I park in a heated garage, I wanted the proven low temp performance of such synthetic oils

Mobil 1 5W-30 should be good to -40, though if you were to consistently operate at -40 a 0W-30, especially a 0W-20, would be far more appropriate. So don't worry about that trip

Good observation about whether they will use your own oil. I've posted the virgin oil analysis of that wonderful "Toyota spec" dealer bulk oil, I wouldn't use that s*** in an old broken down lawnmower

Makes one wonder why Toyota got burned by an engine sludge class action suit, and why they universially lowered the North American oil change interval from 12 months/7,500 miles to 6 months/5,000 miles.

The European Toyota spec remains at 12 months or 10,000 miles

The only way to know for sure if they use your oil is if you watch every step. I'm not saying every dealership is a scam artist, but enough are to make me suspicious

Remember that even current API SM/ILSAC GF-4 will *not* prevent ring land deposits, crown land deposits, cold gellation, or cold sludge, as there is no specific requirement to do so. The ACEA spec oils *do* have to minimise/prevent those sort of deposits

Mobil 1 5W-30 is dual rated API/ACEA. Don't waste your money on the Extended Performance, it carries the same ACEA ratings

If you really want an superior ACEA oil, consider Mobil 1 0W-40, which is the oil I use in my FJ Cruiser. It meets the toughest ACEA specs: A3, B3/B4. Around here, priced the same as the other Mobil 1 oils. I don't think you need an oil like that in the Prius

Running Mobil 1 0W-20 up to 16,000 km and 12 months, the oil tested fine

 

I see I wasn't the only person thinking that ...

 

Great work finding out about the oil properties......I need to have my oil changed and will think about what to use......