So Will, do you have a long commute every day or do you take lots of long trips? How long do you go between filter changes?
I'm curious to see those used oil analyses. Please post them. I don't know what property of synthetic oils would give you a 7% fuel economy increase. Amsoil says "AMSOIL Synthetic 10W-30 Motor Oil is designed to maximize energy efficiency for improved fuel economy. Unlike conventional oils, its uniform molecular structure helps it flow more freely and reduce friction between metal surfaces. Anti-friction additives are included to further improve energy efficiency." The problems with that statement are that once the oil is up to operating temperature, it's a 30 weight oil, just as it says on the bottle, so it doesn't flow any better than any other 30 weight oil, plus every motor oil contains anti-friction additives. If Amsoil thought you could get a 7% increase in gas mileage and save $400, they would tell you that to try and sell more oil, but they don't make any such claims. They include all sorts of 4-ball wear tests and other useless marketing B.S., but they don't tell you that you can get much better gas mileage. That just doesn't add up. I don't believe the mileage numbers you've quoted have anything to do with synthetic oil for that reason.
Here is what Mobil 1 says:
"What's the overall benefit of Mobil 1 with SuperSyn Technology?
Mobil 1 with SuperSyn Technology exceeds the latest industry and OEM requirements. It is designed for vehicles under warranty and will provide protection for the maximum oil change interval recommended in your owner's manual or by your oil life sensor.
The overall goal for Mobil 1 has always been to protect your engine, even under the most severe conditions, such as cold starting temperatures, extreme high-temperature operations and high-load conditions. Mobil 1 has been formulated with a performance reserve to provide you the peace of mind that your engine is protected during these severe conditions. But Mobil 1 with SuperSyn is not just for extreme service. You can also realize Mobil 1's benefits of improved engine cleanliness and extended engine life under "normal" service."
Nothing at all in there about fuel economy increases. Why not? If it's so great for fuel economy, why aren't they advertising it? Royal Purple says up to a 5% fuel economy gain with no numbers to back it up. Maybe you should give them a testimonial?
Compaq888, I can't make any sense out of your post. One one side it sounds like you attribute your gas mileage gain to expensive purple oil. On the other side it sounds like you've done lots of other things to try and gain a few MPG, so you really can't point to the oil as the source of the gain. Either way, you're changing synthetic oil at a 3000 mile interval which is a huge waste of time and money. Any gas savings you have from doing that is more than wiped out by your oil change practices. What exactly are you trying to accomplish with your tweaking and tuning? Money savings? If that's the case, I think you could do much better by changing to conventional motor oil, which is recommended by Nissan by the way, and doing a used oil analysis to help you determine what interval would be both safe and also cost less money. Try Blackstone Labs or Dyson Oil Analysis or any one of the many oil analysis laboratories out there. It's typically $20. You could save that much on a single oil change by following their advice instead of making up an oil change schedule based on marketing and speculation. Before you do anything, though, decide exactly what it is you are trying to accomplish. Saving money? Saving oil resources? Just trying to get the highest MPG number possible at any cost so you can sound cool on a web site? So you get 1 MPG better. That's terrific, but what does that 1 MPG cost you? The oil is about 3 times as expensive. Do you make that up in the cost of gas? Is it really worth it??? To me, that's the question to be answered on gassavers.org. I'll offer whatever proof and hard data I can to help in those efforts.
Let me clarify a couple of things. I'm not trying to save money. If I wanted to save money all I have to do is turn the car insurance off and park the car and take the bus to school. Which is $23 a month. Compared to $100 for insurance and $100 for gas. $23>$200.
Next, I did a huge maintenance when I bought the car at the end of 04 and it would only get 28mpg on the freeway and at that time I was using mobil 1.
Now I get 40+mpg on the freeway. If you think it's a fluke then let me give you a math lesson. My car gets 20-22mpg on the street and when I fuel up my average is 30mpg. Now if 50% is city driving and 50% is hwy driving what's going to be the hwy number?
30mpg just doesn't come up like that or a couple dozen gas stations have their pumps broken. I'm kinda doing what Matt is doing, building a high mpg car at the fraction of the price. My goal is 35mpg mixed and that's it.
If I wanted to get the highest mpg at any cost I would syphon gas from around the neighborhood. Let me calculate 5 gallons of free gas and I drive for 150 miles. I don't know how to calculate it I guess whatever number of miles you get from stolen gas that's your mpg.
I'll be looking really cool when gas goes back up to $3 and I'm getting 50mpg on freeway. Not only will I look cool on this website but on the freeway too.
Diamond Larry is correct. I am not an Amsoil dealer. I am just someone who tried a product and found that it worked for me. I do drive 25000 miles a year on my truck and every mpg makes a difference to my wallet. Also, it is much more convenient for me to change the oil once a year and knowing that it is protected for that time as I was changing it more often with Dino oil. I was thinking about becoming a dealer at one time but with a family and two small children, I don't have the time.
Filter changes are dependant on analysis data, from 8K to 14K
My oil analysis is an easy single number. Values from 0-9
Test equipment? Northern Technologies International Corporation is the make.
LubriSensor Model NI-2B
This is what they call a portable oil analyzer.
I don't know what property of Syn oils would give me the 7% increase either, cosmicmc.
The analyzer works by comparing new oil, to the sample oil for each analysis. It compares the dielectric propertys of the oil samples. The difference is the number 0-9 (for synthetic, 8 is when you are suposed to change it, but I have gone to nine a few times.)
I've given mobil one testimony by the way, they accepted it and never used it and made me agree that IF they ever do, to not expect any finacial benefits. shrug. Royal Purple is too expensive for me to consider giving them testimony.
And maybe there are just too many variables to go start making claims about fuel economy with mobil one. Maybe if they did, and ppl using thier products, away from the labs controlled test situations would start kicking and screaming "false claim, false claim" and woah, with the internet being ever so popular, them ppl could really put a dent in Mobil ones reputation. So they just don't put it out there, better safe than sorry?
"You have to know the truth, and seek the truth, and the truth will set you free."
I think the oil analyzer is useless for the purposes you use it for. It is designed for use with large diesel engines and diesel engine oils, not gasoline car engines. They are two completely different beasts. On top of that, the dielectric constant is only one of the four factors they use to determine the lifespan of the oil. The guy who's writing his story about using it is also using it with a diesel engine and Mobil Delvac diesel engine oil. Gas engines don't produce the soot that diesel engines do, and they also don't acidify the oil like a diesel does. The chemistry they used to design the analyzer is totally different from what your engines see, and for that reason I wouldn't trust that thing to tell me when to change my oil. A used oil analysis is the only reliable way to do it.
I don't think the synthetic oil is buying you any mileage increases at all. If you can document the exact conditions under which you came up with this number, we can all judge for ourselves. Lacking that information, I chalk it up to a psychological effect or invalid science. If synthetic oils bought you better gas mileage, their advertising departments would be all over it, especially with gas prices where they are. But strangely, they don't advertise that. Doesn't make any sense to me.
I'm not judging you, but I don't think your testimony holds water. I've been wrong before, so somebody rip my ideas apart and show me why I'm wrong.
Switching to synthetic lubricants - - engine oil, diff, Amsoil C+ Mopar-spec
transmission fluid, and syn greases in wheel bearings is good for 2-5% MPG
improvement. That is only about 0.5 mpg but every little bit helps.
If you go on to read the rest of that article, as I just did, and you made all the modifications they recommend to save gas mileage, your mileage would go up by a minimum of 7.45 MPG, which would be about 40% better mileage than advertised on the window stickers. What do you think are the chances that Dodge would let a 40% mileage increase pass them by just because they didn't tell you to lower the tailgate, use different tires, index the spark plugs, use synthetic oil, etc. That whole article is a nice heaping, steaming pile of speculation, wild ideas, old husband's tales, and junk science. As if that wasn't enough, they said that lowering the tailgate would increase mileage, but removing it would decrease mileage, which is counter to the water testing that Mythbusters did. Those guys showed that you will get the best mileage with the tailgate UP because the aerodynamics created by the auto manufacturers take the closed tailgate into account in the design and deliberately create a "cushion" of air circulation behind the cab which deflects the airflow over the top of the tailgate so it doesn't create much wind resistance. If you lower the tailgate, the air flow comes down right on top of the tailgate and decreases mileage by increasing aerodynamic drag.
There are a few tiny nuggets of joy in that article, but for the most part it's a whole lot of hogwash, and even those few nuggets of joy cost so much to implement that it would take many, many miles to ever recover the cost of the changes. That's why Dodge didn't do it at the factory. If they wanted better mileage from their vehicles, they shouldn't have bought pickup trucks with 340 horsepower V-8 engines.