I recently had the ICE oil and filter changed for synthetic (Mobil 1). I have been monitoring the gas mileage that I have been getting as well. Right after the oil & filter change, I filled the gas tank and proceeded to replicate the trips that I took with the tank of gas immediately prior to the oil & filter change to see what impact the synthetic oil was having. Low and behold, the fuel mileage went from 42 to 44 mpg.... Now for the financial part: Change Interval:.........................5,000 miles Economy before adding Mobil 1.........42 mpg Economy after adding Mobil 1...........44 mpg Cost of gas...................................3.40 /gallon Gas cost for Interval w/o Mobil 1....$404.76 Gas cost for Interval w/ Mobil 1......$386.36 If you buy Mobil 1 when it is on sale, I have seen prices in the $16 range for 4 quarts, so you would be saving $2 on fuel costs versus the cost of the Mobil 1. (You are also saving the cost of the dyno oil, so the total savings is more; but I don't have numbers immediately at hand for the dyno oil.) For those who want to extend their oil change interval, the benefit goes up (7,500 mile change interval results in a $28 fuel savings; 10,000 mile change interval results in a $37 fuel savings). A 7,500 mile oil change interval with Mobil 1 is probably a safe compromise between reducing cost and increasing benefits. I personally wouldn't go out to a 10,000 mile change interval without a used oil analysis at 7,500 miles. Definitely food for thought.
For me it's not about saving money, it's about saving oil; a non-renewable resource. I may switch to synthetic on my first change (currently only have 2850 miles). How many data points or tanks do you have for your 42-44mpg improvement? I will definitely switch if I can get +2mpg. Thanks for planting the seed...
<div class='quotetop'>QUOTE(likesmpg @ Jul 14 2007, 12:24 PM) [snapback]478712[/snapback]</div> I have the before and after data points. Any additional data after the tank immediately after the switch could be challenged as being contaminated by the engine continuing to get broken-in. By replicating the trips in my last "before" tank with the first "after" tank, I tried to eliminate any variables and get as close as possible to showing the gains from only the switch.
I use Mobil 1 (synthetic) oil and Mobil 1 oil filters. Twice the capacity of the standard oil filter. Inexpensive insurance. About 3 mpg better with synthetic oil (currently at 11.5k mi) on a 2007.
<div class='quotetop'>QUOTE(skruse @ Jul 14 2007, 03:17 PM) [snapback]478773[/snapback]</div> I also use Mobil 1 synthetic oil. I average between 45- 50 mpg all the time. My freeway speeds average 60 mph around 2800 miles a month. I use the Toyota oil filter. Something about the bypass valve that is built into it prevents the oil from draining back into the pan. Someone on here will point you to the threads that discuss this. I think it prevents dry starts of the ICE after it sits all night. Valve trains and other key parts that need oil should not wait for the oil pump to finally squirt oil to the valve cams, valve lifter, ring seals etc. If I'm wrong, someone will correct me. I think I notice better mileage too from using the M1 oil, but I only used dino for the first 5K miles, then switched to the M1. But I don't keep meticulous records like some of the folks out here so eyeball and fish story logic are my rule of thumb. I do about 80% of my own oil changes, If a good coupon comes out, and I'm in the area of Longo toyota, I will have them do it. I have done a few 10 K mile intervals, but most are at 5K. currently at 64K on a 2005 - 1 month shy of two years. Any-hooz-it, good luck.
I use synthetic but not because of any hypothetical fuel economy benefit. Like a prior poster my intent is to extend the oil change intervals. I've started having the used oil analyzed to keep track of how the engine is really wearing. The first oil change on M1 @ 5,000mi came back with plenty of life left so I'll go another 1,000 on this fill. There's zero cash savings in this but I'll use less motor oil and have the peace of mind that comes with that oil analysis.
<div class='quotetop'>QUOTE(likesmpg @ Jul 14 2007, 12:24 PM) [snapback]478712[/snapback]</div> An additional thought occurred - this time in regard to conserving resources.... If you increase the fuel economy, you are burning less gas and thereby reducing CO2 emissions. Is it worth being able to reduce CO2 emissions while at the same time saving on operating costs? That sounds like a win-win!
<div class='quotetop'>QUOTE(KD6HDX @ Jul 14 2007, 06:03 PM) [snapback]478800[/snapback]</div> The anti drain-back valve is of no use on the prius since the filter is mounted vertically with the opening on the top. Gravity keeps oil in the filter. If it were mounted horizontally, it would be useful. Amsoil makes an excellent filter: http://www.amsoil.com/StoreFront/eao.aspx The prius takes the EAO-09. I change the filter at 12,500 and the oil at 25,000 miles.
<div class='quotetop'>QUOTE(apriusfan @ Jul 14 2007, 02:11 PM) [snapback]478709[/snapback]</div> If money is that important to you, why do you own a Prius? You can buy a cheap Kia for a third of the price of the Prius, and have a lot more money in your pocket!
<div class='quotetop'>QUOTE(Per @ Jul 15 2007, 09:23 PM) [snapback]479437[/snapback]</div> Money in this instance is a measure of the effectiveness of whether to go with synthetic or stay with non-synthetic motor oil. If you have some other objective standard that does a better job of assessing the benefits of synthetic versus non-synthetic motor oil, please share.
Fuel economy has nothing to do with my reasons for using Mobil 1. For me, it all comes down to the superior protection 100% synthetic oil provides, especially in reducing engine sludge. Synthetics almost always have superior additives than petroleum oils. While this does add to the cost of the oil, it also enables the synthetics to last 3-5 times longer than conventional oil. Because a synthetic oil is chemically produced, there are no contaminants in the oil. By contrast, conventional oils contain small amounts of sulfur, wax, and asphaltic material that can promote detonation as well as varnish and sludge buildup. Also, in colder climates, synthetics perform better because of the various paraffins that are contained in all petroleum products (regardless of how well refined they are) cause petroleum oil to jell like a syrup at extremely cold temperatures. Just remember that Mobil 1 is not the only synthetic motor oil on the market. Take a gander at some of the discussion on the boards over at Bob is the Oil Guy (http://theoildrop.server101.com/forums/ubbthreads.php) and you will see that Wal-Mart's SuperTech synthetic performs nearly as well as Mobil 1, but at only a fraction of the cost. So, if you are truly balancing cost and performance, maybe this is the route for you.
Also, don't forget that the overall cost of synthetic oil is lower if you actually run it longer than 5,000 mile intervals. You can easily get 10,000 mile intervals out of Mobil 1, as is evidenced by some of the used oil analysis posted on this site.
<div class='quotetop'>QUOTE(Per @ Jul 16 2007, 05:28 AM) [snapback]479533[/snapback]</div> I am fairly well-versed on the difference in (and benefits of) synthetic versus non-synthetic motor oil. My purpose in starting the thread was to provide another perspective on whether to go with synthetic. In my experience, if someone is wavering about whether to use synthetic motor oil or not and you can show them that in addition to all of the other benefits, they are going to save money by adopting synthetic, the argument for synthetic becomes that much more compelling.
<div class='quotetop'>QUOTE(Swanny1172 @ Jul 16 2007, 07:52 AM) [snapback]479580[/snapback]</div> Really (about fuel economy having nothing to do with your reasons for using Mobil 1)? Just playing devils advocate, but what if fuel economy took a 10% hit; would you still go with synthetic? 25% hit???? At some point, the cost of operation cancels out other non-operational considerations. I am not being argumentative, but I think that cost (whether it is initial acquisition and/or operating) affects all of us. <div class='quotetop'>QUOTE(Swanny1172 @ Jul 16 2007, 07:52 AM) [snapback]479580[/snapback]</div> No issue here. My purpose was to make the case for synthetic oil (in my instance, Mobil 1). When one gets over the hurdle of whether to go with synthetic, then there is another decision as to which one. That (which one) is beyond the scope of this thread.
