new (believe it or not) info about Oil Changes

It's interesting that you would deduct the mileage that the engine is not running. I would think that the time not running has other considerations, too. Starts are hard on an engine, with possibly more wear associated with the process than just running, but since the engine does not idle much, a time when wear is also higher, it avoids the vibrations and fuel dilution of no load running. I think that I'm going to use a synthetic oil to help with the startup process. I'm just wondering if using a formula like gallons of gas burned would be better than time or mileage. During a time when your mileage is low you might be working your engine harder and it would be good to change your oil sooner. As previously posted, oil lasting 20k mileage is only possible in the best of engine and driving conditions with a careful driver. It might not apply to everyone and it would only be possible with the help of oil analysis. Otherwise it's a risk. The cost of oil analysis, with TBN and particle counts, is more than an oil change so most dirvers would just ignore the maintenance or change the oil one more time.

 

<div class='quotetop'>QUOTE(efusco @ Nov 18 2006, 02:11 PM) [snapback]351496[/snapback]</div>

Having oil pressure is great. It does not completely eliminate lubrication problems associated with starting and stopping an engine. It's becaus of this kind of operation that I'm going to use synthetic oil, specifically a POE based oil because I think it will do a marginally better job of dealing with bearing lubrication when those shafts start and stop, frequently. Toyota has done a really good job of managing the start cycle and if I can ever figure out how the transmission works I'll be a happy camper.

 

I have used Mobil 1 in all my Vehicles for over 20 Years, including a Pro Stock Drag car! Back in the 80's Mobil1 used to advertise 25K miles for a filter change and 50K miles for an oil change. Now since then the performance of Mobil 1 has increased and the friction on internal engine components has decreased so why is it that the Mobil no has a "long life" oil that is 15K miles between changes. Additionally given that the cost of Synthetic Oil has risen greatly due to demand not due to manufacturing costs or raw material shortage. My opinion would be that the shorter change inter is strictly a mater of profit. So now that I am off my soap box, as I stated I have been using Mobil 1 for aver 20 years and I have always went 10K miles (except for the race car) with no ill affects and cleaner oil after 150K miles of use than using conventional oil and a 3K interval. Regardless of when you change do it with Mobil 1

 

<div class='quotetop'>QUOTE(efrench515 @ Nov 18 2006, 05:52 PM) [snapback]351536[/snapback]</div>

I only remember them saying follow the vehicle manufacturer's schedule. Mobil's advertising and price say extended performance for the Mobil 1 EP but no one has been able to figure out the difference between Mobil 1 and Mobil 1 EP by used oil analysis or lab analysis. It is possible that EP is a better oil. Mobil 1 is a good oil but it's too expensive. Many Group III oils at a cheaper price proform equal to or better based on used oil analysis. Mobil 1 is a synthetic based on the legal definition of synthetic but it's major component is Group III. To confirm the performance by used oil analysis you can go to bobistheoilguy.com. Look in the UOA section. Mobil 1 is an average oil with great marketing.

<div class='quotetop'>QUOTE(john1701a @ Nov 18 2006, 04:42 PM) [snapback]351529[/snapback]</div>

John, thanks for the PSD info. I sat down with a calculator and some paper and I think I've got it. There is a lot of computing going on inside the Prius.

 

In Europe, oil interval change for Prius is 15 000 km (9300 mi) but most carmakers are 30 000 km (18 750 mi) :blink: