Use of synthetic motor oil and mud flaps

The mud flaps on mine have had no impact on MPGs, but resourceful mud finds a way to hit the fenders anyway. Worth trying if your car is very muddy now. Mine came from Canada, but they are at some US dealers now. http://www.sigmaauto.com/jdm/prius/prius0405.php might have them.

Synthetic doesn't seem to jack my MPGs up higher than anyone using regular oil. All I can hope for is that if sludge was going to kill my engine, something else will have to take over for it...

 

Mud flaps- useful only if your car frequently gets very dirty. Synthtetic oil- useful only if you think that your car is actually a person who deserves the best. If you understand that the Prius is just a car, it's not necessary. The Prius engine never overheats, is off in traffic jams, peaks at 5000 rpms, produces 76 hp...

Both are useful to satisfy the urge to shop and spend money, though.

 

I second that. But I refer to my Prius as my baby.
So I do have both mudflaps and Mobil 1 super syn for my baby. :wub:

 

Is Mobil 1 yet making 0W-20 or 5w-20?

Oh, and for us yet-to-be-owners... what's the recommended viscosity?

 

I have to humbly dissent from this opinion about synthetic oil. Synthetic oil is actually made mostly from petroleum, but it has gone through a number of chemical processes that give much more consistent size to the molecules. A good synthetic oil will lubricate better than a regular one, especially at very low and very high temperatures. You may get slightly better mileage and should get greater longevity to the engine, if that matters to you. Conventional wisdom (sometimes disputed) is that you should wait until your engine is fully broken in before switching to synthetic because the enhanced lubrication will prevent the internal wear needed for break-in. In any case, I plan to switch to Valvoline synthetic (see below) at the first oil change of my new '06.

Do keep in mind, thought, that not all synthetics are better than all regular oils. Mobil 1, which is no doubt the most commonly used synthetic, has tested well, as has Valvoline full synthetic, which is available at discount stores. Either one is a good choice, costing about $2.50/Qt more than regular. That comes to an additional $10 per oil change, every 5,000 miles. Cheap insurance, for my money, although (obviously) not everyone agrees.

 

At 10,000 miles, I switched to Mobil-1 5W30 (the weight recommended by the Prius manual). Also, my dealer WILL use the oil I provide = 3½ quarts which brings the level to about 2/3 between the "low" and "full" dimples on the oil stick allowing for the dealer's replacement of the oil filter. This assures "no overfill" which many Prius owners feel is harmful to the ICE and mileage. I noticed no perceptable difference in mileage after the change to synthetic.

 

I also switched to Mobil 1 5W 30 at about 10k miles. I now run 6k miles between changes. Do the math on cost of oil change versus extended warranty, it's interesting.
I heard the Honda Incyte is supposed to use 0W20 but I have not located a reatailer or Honda dealer who sells this. I try to run 0W30 or 0W40 in the winter.
Again, no change in mileage detected. I also tried some expensive oil additives with no measurable results.

 

I'm going to continue to run dino 5W/30 for now, but I plan to change over to Royal Purple synthetic at 10,000 miles, get an oil analysis done at 4,000-5,000, and see if I can extend the oil change interval significantly.
The Royal Purple is supposedly super-slick, and also adheres itself to the moving parts, so that dry-starts aren't as harmful. With all the stopping and starting the ICE does, it could probably benefit from that, IMHO.
Has anyone else heard of Lube Control?

 

Dry starts shouldn't be a problem for the Prius. The oil filter is positioned properly to hold its contents at shutdown without any need for a back flow valve, although all filters have them, now. The oil pump design is such that oil pressure is instantanious upon even the slighest movement of the crankshaft.

I moved over to M1 5w30 at my first oil change. I'm not convinced that I've seen any significant FE benefit, however I do believe that M1 and other synthetics are better able to susped soots and contamination than dino oil and full synthetics are much better at resisting sludging. Correct me if I'm wrong, but sludging is basically a product of running dirty oil so long that the contaminants overpower the ability of the oil to trap them and as such they becomd deposits in all kinds of places we don't want deposits. All the oil analysis results we have seen posted here indicate that the Prius is pretty nice to oil. Probably indicating a longer change out life, especially with syn oil. European Prii all have a 10k mile oil change specification.

However, as NA owners, we are all going to be held to the 5k change limit.

As for mudflaps, that is an item of personal taste. I'm sure they will protect the fenders and sides of teh vehicle from rock and slush, however if your weather is moderate they might not be all that useful.

 

I use Mobil 1 synthetic 5W30. However there is no "Energy Conserving" designation indicated on the container. What's the significance of this designation? It appears that those of us using synthetic [e.g. Mobil 1] are doing so even though the "Energy Conserving" designation is not indicated. Any thoughts on this?

 

I have a few cases of 5W-40 Hi-Perf oil. Does anyone know if that is acceptable in the Prius? Thanks.

 

I'm dredging up this old thread.

200Volts, how is the Mobil1 0w40 in your Prius working out for you?