Synthetic Oil vs. Natural Oil
 

I just had my oil changed today and they put in synthetic oil. Instantly I noticed my RPMs were lower. Usually my car idles between 1200rpm and 1500rpm (I know this is high, but I havn't adjusted it yet) and now it is idling around 1000rpm.

Has anyone else noticed this when switching to synthetic? I know that there has been a debate on the benefits of switching to synthetic for years, but it seems to me to be a no-brainer.

I havn't noticed a mpg gain yet, as I've only driving about 10 miles since getting my oil changed, but the lower RPMs indicate that I WILL get a MPG gain from switching to synthetic.


What say you?

I've always seen noticeable
 

I've always seen noticeable increases in gas mileage running synthetics. All of my vehicles have synthetic lubricants from bumper to bumper. However... one would think since your rpms decreased your mileage would too! Ideally you should see higher rpms at the same throttle position and fuel flow. In the past I've often had to adjust idle speeds down because the use of synthetics would increase my idle rpms. Also, all synthetics are NOT the same. Some major brand names at one time were pretty decent. They have since reformulated to lower grade hydro cracked base stocks (though the kept prices the same as when they had the higher quality POA's).

Hmm
 

Interesting idea nrgrebel, I've never heard this before, I'd like to do some research on it, as it makes sense, I think. If you're at a higher rpm for game energy output would you not be making more power for the same fuel flow?

In any case, Matt, what viscosity of oil did they put it, not 0w30 was it? ^_^, I wanna put that in my car next time, but right now it's idling at 750, just so you get and idea.

Re: Hmm
 

They put 10w30 in my car. I might put 0w30 in my engine after the swap, but I don't want to do anything too drastic until after the engine is swapped.

I guess this weekend will be a good measure of my gas mileage. I'm driving from Salt Lake City, UT to Las Vegas, NV tomorrow morning. This will be my base mileage, and then on the way back I'll put acetone in the gas tank and measure my mileage on the way up. I'll also monitor RPM and speed in the event that going uphill/downhill have any effect on the gas mileage.

Cool
 

Don't forget to pull your negative cable or hazard fuse for a few minutes to reset the ecu after you have let the acetone mix in a little bit.

my understanding of
 

my understanding of synthetic vs mineral is that you'll notice an efficiency improvement at low temps only. synthetic has better viscosity stability and pourability than equivalent weight mineral oils at low temperatures (mineral gets much thicker).

so the only time the engine is running more efficiently on synthetics is from start-up until it reaches normal operating temperature. once warmed, there's no difference.

have a read through mobiloil.com - you'll see they don't promise efficiency gains. just improved performance under "extreme" conditions. if they could promise gains in mpg across the board, you can be sure it would be all over their marketing.

Older Engines Beware
 

Since the molecule size of synthetic oil is much smaller than mineral-based oils, older/higher mileage engines tend to leak or burn synthetic pretty quickly as it creeps between old gaskets, seals, and rings. Just keep an eye on the level over time...

RH77

Synthetic vs Natural Oil
 

Here is an email that I received from an Amsoil dealer and member of Society of Automotive Engineers. I'm partial to Amsoil as I've tested it and use it in both my vehicles. I've noticed a solid 1 mpg gain in my F150 pickup.

Thanks for the update James. AMSOIL Series 2000 0W-30 Severe Service is one of the very best and is a 35,000 mile/1-year oil. Change the AMSOL Super Duty oil filter every 12,500 miles/6-months (note that this fall AMSOIL has 25,000 mile oil filters coming out, an exclusive industry first patented nanofiber technology). If you do not put 35,000 miles per year on then the 5W-30 (ASL) or the 10W-30 (ATM) are also excellent choices and both are 25,000 mile/1-year lubricants. All AMSOIL Synthetic Lubricants meet and far exceed all manufacturer specifications as well as API Specifications.

AMSOIL Series 3000 5W-30 HDD is the most advanced chemistry product AMSOIL offers and is also a 25,000 mile/1-year oil in non-commercial gas engine passenger cars and light truck applications. It has the beefiest additive package of all AMSOIL motor oils and resists oil breakdown from heat, blow-by chemicals and oxygen up to 10 times longer than conventional oils. It is also an excellent severe duty fleet type oil for applications such as police and delivery fleets.

the AMSOIL Series 2000 0W-30 Severe Service is a racing oil and of a different chemistry than the 10W-30 and 5W-30. I have been a Ford Engineer and Lubrication Specialist for over 20 years and we often use the 0W-30 in the 800 Hp Ford/Roush Nascars as it has a shear strength better than most 50W oils and transfers heat more efficiently than heavier oils. Only about 60% of the engine cooling is done by the coolant and the rest is done by the oil via heat transfer. The 10W-30 and 5W-30 would not be good choices for racing. The 5W-30 ASL product code and 10W-30 ATM are both 25,000 mile/1-year oils where the 0W-30 is a 35,000 mile/1-year oil. The 4-ball wear test is also run at a different load, temp and RPM than the other 2 products so they cannnot be compared in that area. The 0W-30 does not thin out to a 0W as it gets hot. It stays a 30W just like the 10W-30 and the 5W-30. They are ALL 30 weight oils and each one can be beneficial in a specific application. The 10W-30 is a better oil under certain instances for higher mileage engines as it has a lower volatility. 10W-40 High Performance is a heavier duty oil for severe off road, towing and RV type use and is also a 25,000 mile/1-year oil.

I am here to help anytime and if you decide to become a dealer please let me know.

Best Regards,
*
Dave Mann
Lubrication Specialist - Truck/Automotive Engineer
Society of Automotive Engineers Professional Member
Performance Oil Technology, L.L.C.
www.performanceoiltechnology.com
1-888-879-1362
*
Detroit Office:
2125 Newport Ct.
Wolverine Lake, MI 48390
Northern Office:
3698 Leeside Lane
Traverse City, MI 49686*
Mailing Address:
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Synthetic = mostly useless
 

The debate about synthetics versus dino oil usually turns into a religious one rather than one based on facts. People hear some slick marketing somewhere and it gets stuck in their heads as the word of god. The fact is that synthetic oil has some properties that are technically superior to conventional motor oils. Another fact is that in most circumstances, those technical superiorities don't amount to much more than a tiny hill of beans when it comes to engine longevity and fuel efficiency, and they will probably cost you more money in the long run.

jamescartagena's post above removes a lot of credibility from this entire web site. He wants you to buy Amsoil and become an Amsoil dealer not because it's good for you or your car or your wallet but because it benefits his wallet. He's a salesman, and he's here because he doesn't want to pay for advertisements. It's unfortunate that the administration of gassavers.org allows someone to advertise for free on the site. Amsoil is a multi-level marketing scheme. You know the difference between a dead possum on the highway and a dead Amsoil salesman on the highway? There are swerve marks before the possum.

So let's use Amsoil synthetics as an example of how synthetics are mostly useless. This is an easy one. Amsoil says certain of their products are good for 25,000 miles or 1 year. That's for normal driving. For severe service it's 15,000 miles or 1 year. All of that depends on you using an Amsoil oil filter and changing it in 6 months or half the mileage interval. That oil costs $6.35 per quart, and the filters are $10-$12 each. A name-brand, high-quality conventional motor oil costs about $2.00 per quart, and you can get a high-quality oil filter for $5-$6. so Amsoil costs over 3x more than regular oil. OK, so let's say your car takes 4 quarts of oil, your driving doesn't fall into the severe service category, and you drive 12,500 miles per year.

Here's the scenario: You have a recent model GM car with the Oil Life Monitor system that calculates the remaining lifetime of your motor oil based on mileage, temperatures, engine RPMs, and other factors. You changed your oil with Havoline 10W-30 and a $5.00 AC-Delco oil filter one year ago and drove 11,000 miles, and the Oil Change light just illuminated on your dashboard. You do a used oil analysis on that used conventional oil at a cost of $20 and it shows that the oil was protecting your engine just fine when you drained it. So your oil change cost you a total of $13 and with the analysis $33.

If you had used Amsoil, you would have paid $25.40 for the 4 quarts of oil, plus another $20-$24 for two Amsoil filters, so without even doing the analysis, you have already paid $47 for an oil change instead of $13. You have the analysis done on the Amsoil oil and you find that it also was protecting your engine just fine. What have you gained by using Amsoil? Was it worth the 362% higher cost of Amsoil?

The days of 3000 mile oil changes are gone, but that's what Amsoil still quotes in their numbers, and the latest Oil Life Monitor system from GM will extend your oil change interval to 12,500 miles if you drive the car normally and not in severe service. GM wouldn't tell you to go 12,500 miles before getting an oil change if it was going to damage your engine because it would give them an even worse reputation for quality compared to the Japanese automakers. New engines and new engine oils are far, far better than they were even a few years ago, and as time goes on, Amsoil and synthetic oils in general become less and less relevant. They'll quote you all kinds of 4-ball wear tests and tons and tons of totally irrelevant facts and statistics. All you need to remember is this: When was the last time you heard of somebody who changed their oil regularly with ANY kind of oil having their engine die an early death because of lubrication problems? That's all that matters really, but Amsoil would like you to believe your car won't last as long with regular oil. Think for yourself about it. Have you ever heard of such a problem? By the time a car gets that many miles on it, so many other things would have broken and been replaced that the engine would be cheap by comparison.

Do yourself a favor and avoid Amsoil and other synthetic oils. Put the money you save in your vacation or retirement account, donate it to a worthy charity, or take your special someone out for dinner. Don't give it to an oil salesman for a mostly useless product.

Molecule size
 

The "molecule size" of synthetic oil is not "much smaller" than mineral-based motor oils. The only difference is that synthetics have a more uniform size than mineral oils do. Synthetics are made from natural gas and some other things, not refined from crude oil. Refining is not a perfect process. Some heavier and some lighter things are left in there such as paraffin and benzene. Modern refining has reduced the level of those items to very, very small levels, and in fact some oils marketed as "synthetic" are really just mineral oils that have gone through extra refining steps. This might include some Amsoil products. Synthetics do not cause leaks and it doesn't creep between anything any more than mineral oil does. The additives in synthetic oils may harden or otherwise affect some older seals, and if those seals are already mechanically compromised in some way, leaks can happen where they weren't before, but the root cause is really the mechanical degradation of the engine and not the synthetic oil.

You don't need to avoid synthetics because of worries about leaks. Avoid them because they aren't worth 3x the price, the benefits in reality are negligible or zero, and the salesmen can be slimy, greedy, lying scumbags who pull all kinds of tricks to try and dupe you into buying their products.