Myth or Fact: Synthetic Increases MPG

[Capa]

Originally Posted By: Vikas
>>Over 5 fillups MPG has improved maybe 0.5MPG; ranged 26-28.5.
Please don't think I am picking on you but with the variation of 2.5 mpg, how in the world can you claim that you got improvement of 0.5 mpg? Your gains are well under your margin of error.

You are not the first one and I am sure you will not be the last one to make similar claims.

- Vikas


Mobil AFE, for example, claims about a 2% boost in fuel economy. I haven't seen any claims of major fuel economy boost by legit oil companies. Nonetheless, there are plenty of studies that show that synthetic oil + 0W + friction modifiers (etc) do give a measurable, albeit not major, fuel economy boost. Many people on this forum have confirmed this as well. I, myself, have seen about a 2% boost going from dino to syn. If you want to pretend that that is within the margin of error and there is no real fuel economy boost, it is your loss.

 

[oldmaninsc]

Quote:
If you want to pretend that that is within the margin of error and there is no real fuel economy boost, it is your loss.


You miss the whole point. I drive the same route in my Mercury and the same streets everyday of the week, and I get between 19 - 21 MPG. Two percent of 21 is .42 On the street in everyday use it's just too hard to measure.

Even on the long trips I take to Phoenix three to six times a year (roughly 400 miles one way) the MPG can vary by about 1 - 2 MPG based on traffic, weather and various other factors. So while in a lab on a dynamometer there may very well be a 2 percent increase, the point is in everyday driving it is really hard to tell.

I'm always skeptical of people who say something like 'I changed to syn. oil and gained 5 MPG'

That being said - I like and have been using Pennzoil Ultra and Platinum in the Mercury. Am I wasting my money? Maybe, but I feel it's ONE of the best oils out there and suits my needs.

 

[Capa]

I'm not questioning that the real mpg gains that certain synthetics provide are minimal and hard to measure; I'm questioning the reasoning that the real gains are imaginary. They are real and whereas they are difficult to measure in one tankful, nonetheless, when your OCI is 8000 miles or so, there is certainly $$$ saved. I also go back and forth between 100% E free gas and 10% ethanol and the difference is close to 4% and also hard to measure. Nonetheless, the mpg gain is there and it certainly saves $$$.

Of course, when people are claiming 20% or more mpg gain on syn, it should be questioned. Personally, I've gone from 0W-30 (20.94) to 5W-30 (20.32) to 0W-40 (19.71) and have seen a slight loss of mpg with the progression of these syn oils. The oil each time was run for about 10 months. I intend to try 0W-20 now in the same Lexus V8.

 

[JAG]

Polymer (aka polymeric) esters are a very interesting type of esters discussed here: Rudnick book

 

[Capa]

Originally Posted By: JAG
Polymer (aka polymeric) esters are a very interesting type of esters discussed here: Rudnick book


Man, that was a long read. It looks like my conclusions have been justifued since I've always preferred polyester

 

[circuitsmith]

Originally Posted By: Vikas
>>Over 5 fillups MPG has improved maybe 0.5MPG; ranged 26-28.5.
Please don't think I am picking on you but with the variation of 2.5 mpg, how in the world can you claim that you got improvement of 0.5 mpg? Your gains are well under your margin of error.
- Vikas


The key word is MAYBE.
In previous years I never got over 28MPG around that time of year and got some tanks under 26MPG.
My lowest ever in the winter was 23MPG

 

[iunderpressure]

I know gas mileage depends on a lot of things, but I drive enough and watch my mileage with every fill up that I can clearly see shifts with mileage using different oils. I perfer synthetics over dino.

 

[fpracha]

Originally Posted By: Capa
Originally Posted By: Vikas
>>Over 5 fillups MPG has improved maybe 0.5MPG; ranged 26-28.5. Your gains are well under your margin of error.
there are plenty of studies that show that synthetic oil + 0W + friction modifiers (etc) do give a measurable, albeit not major, fuel economy boost.
I, myself, have seen about a 2% boost going from dino to syn.
OK good improvement even if 2% imho. So what dino grade/brand were you using and what synthetic grade/brand your switched over to, and noticed these gains in mpg?

 

[Capa]

The dino was the Lexus installed 5W-30. The syn was Mobil 0W-30. As stated earlier, the improvement was around 2%, which is basically what Mobil claims. Nothing substantial but since I do a yearly OCI the $$$ adds up. I've since then switched between syn but am looking very forward to trying AFE 0W-20.

 

[Mr_Incredible]

In my personal experience, it's a myth.

When my truck was new I used QS conventional 5w-30 for the first 10k miles. The next 10k miles I used M1 5w-30. Looking at the gas records for those 20k miles, there wasn't even .1 mpg difference between the two oils. Temps and seasons were approximately the same. Highway types were the same. Driver was the same. Everything was the same.

Trans fluid and rear end fluids are where the gains can be found.

 

[gfh77665]

Originally Posted By: mercuryblues

If my car is averaging 20 MPG and if I do get a 2% increase, that will only push the average to 20.4 MPG. However, that increase has the potential to save me a tankful of gas each year (about a $70 savings).



It doesn't have to even do 0.4 MPG for syns to be a great bargain. If you do the math, even a 0.1 MPG savings, over a 7500 mile interval, makes the syn oil free. For those who obsess over finding "bargains" out there, they should buy syns every...single...time.

 

[fpracha]

Originally Posted By: CATERHAM
What you can say, is that the most fuel efficient oils are synthetic but simply being labelled as synthetic doesn't make an oil more fuel efficient.
But the MPG gains will be quite minimal and not really figure into the cost comparison of the high quality dino oils with the high quality synthetics! At least the Synthetics vs. dinos price differencial cannot be justified through fuel savings.

 

[fpracha]

Originally Posted By: gfh77665
Originally Posted By: mercuryblues
If my car is averaging 20 MPG and if I do get a 2% increase, that will only push the average to 20.4 MPG. However, that increase has the potential to save me a tankful of gas each year (about a $70 savings).
Originally Posted By: Capa
I've also seen a slight increase in mileage going to synthetic. Of course, I was using Mobil AFE, which does claim about a 2% gain, which is exactly what I saw.
I thought I saw Caterham post that Toyota claims to save around $8 per 5000 miles with their 0W-20 syn vs 5W-20 mineral. Perhaps he will chime in.
It doesn't have to even do 0.4 MPG for syns to be a great bargain. If you do the math, even a 0.1 MPG savings, over a 7500 mile interval, makes the syn oil free.
Can you please state the math on this.... i'm unable to get $70 or even $15 savings on the 0.1 MPG improvement for 7500 miles. thanks,

 

[Coprolite]

Assume 20 mpg baseline at $4 gasoline with a 1% improvement. Over 7500 miles it would be about $15 saved in gasoline. M1 AFE/PP costs $24.50 locally, with PYB in the low teens (I believe).

I don't use the oil specifically for MPG, but if it saves me 2-4%, it covers the cost differential which I would have paid in either case.

 

[fpracha]

Originally Posted By: Coprolite
Originally Posted By: fpracha
Can you please state the math on this.... i'm unable to get $70 or even $15 savings on the 0.1 MPG improvement for 7500 miles. thanks,
Assume 20 mpg baseline at $4 gasoline with a 1% improvement. Over 7500 miles it would be about $15 saved in gasoline. M1 AFE/PP costs $24.50 locally, with PYB in the low teens (I believe).
Yes but it will be max $7.5 savings over 7500miles in case of a 0.1 mpg improvement! ...and $7.5 will definitely not pay for the M1 oil fill!

 

[KrisZ]

Originally Posted By: Coprolite
Assume 20 mpg baseline at $4 gasoline with a 1% improvement. Over 7500 miles it would be about $15 saved in gasoline. M1 AFE/PP costs $24.50 locally, with PYB in the low teens (I believe).

I don't use the oil specifically for MPG, but if it saves me 2-4%, it covers the cost differential which I would have paid in either case.


Assuming is great, but can you post some actual saving that YOU had? All this talk about “I noticed fuel savings” or “My car shows that it uses less fuel” is meaningless. Unless someone comes out with a detail fuel log over at least one OCI on dino and then the same fuel log on synthetic, we cannot have a meaningful discussion.

In reality it’s the lighter oils that save fuel, not because the oil is synthetic. And even with lighter oil, the fuel saving can only be recorded in a lab, meaning the real world use will not see any measurable difference that wouldn’t be considered noise.

Also, few people seem to realize why manufacturers suddenly moved to 0w20 oils. It is not to save you money, quite contrary, people will pay way more for oil changes since the oil is synthetic. The name of the game is CAFE. If manufacturers can record a fraction of a percent in fuel savings by switching to 0w20 oil, they can multiply that number by the amount of cars they sale annually. So for manufacturers, the "fuel savings" will be big enough to get CAFE credits, even though there will be negligible difference in real world driving conditions. It's the same business with how CAFE MPGs are achieved by manufacturers. More and more cars have high sticker gas mileage, but fail to achieve it in real world, because the pressure is to meet government standards that do not reflect reality.

 

[Vikas]

This forum has lot more people who do not believe in evolution if you know what I mean. There is no point in bringing science where the religion rules. I can assure you that synthetic increases mpg is a religious dogma to them and there is no point arguing otherwise. Scientific reasoning will not sway them.

- Vikas

 

[dave1251]

Originally Posted By: Vikas
This forum has lot more people who do not believe in evolution if you know what I mean. There is no point in bringing science where the religion rules. I can assure you that synthetic increases mpg is a religious dogma to them and there is no point arguing otherwise. Scientific reasoning will not sway them.

- Vikas


Because there is nothing scientific today that synthetics will provide better fuel economy. If we had this discussion in 1990 I would agree apples to apples synthetic oils will provide better fuel economy. Today it is not even measurable.

 

[JOD]

Originally Posted By: KrisZ


Assuming is great, but can you post some actual saving that YOU had? All this talk about “I noticed fuel savings” or “My car shows that it uses less fuel” is meaningless. Unless someone comes out with a detail fuel log over at least one OCI on dino and then the same fuel log on synthetic, we cannot have a meaningful discussion.


I disagree, strongly. We're talking about very small, incremental gains. No matter how detailed your logs, other variables are going to dominate the equation; temperature, wind, air density, traffic patterns, fuel quality. But just because you can't accurately measure it, doesn't mean it doesn't exist. It just means that the differences are small, and difficult to measure given the other variables.

Originally Posted By: KrisZ
In reality it’s the lighter oils that save fuel, not because the oil is synthetic.


Except that's not really true. It's been demonstrated that synthetic base oils have lower coeff. of friction, so viscosity isn't the ONLY variable that matters.

Originally Posted By: KrisZ
And even with lighter oil, the fuel saving can only be recorded in a lab, meaning the real world use will not see any measurable difference that wouldn’t be considered noise.


I don't really get this reasoning? Yeah, it's a very small, incremental gain. And yeah, it's within the noise of measuring via field tests. But how does that mean the effect doesn't exist? This just doesn't make sense. The lab is "real world". Less friction equals less energy expended, period. Just because the difference is small and difficult to measure in the "real world", it doesn't mean that the gains are any less "real world". It just means that they're difficult to measure given the other variables.

The common retort is something like "well, tire pressure matters more than oil viscosity". Well sure it does, but so what? Does that mean that any gains with a more efficient oil won't exist if I pump up my tires more or less? It's all additive, and oils which offer better fuel economy are just one (small) part of the equation.

Honestly, when the gains are this small, I'll take estimations based on lab reports over field tests any day of the week, unless you have an indoor track closed to all traffic and you're monitoring fuel quality.

 

[dave1251]

Originally Posted By: JOD
Originally Posted By: KrisZ


Assuming is great, but can you post some actual saving that YOU had? All this talk about “I noticed fuel savings” or “My car shows that it uses less fuel” is meaningless. Unless someone comes out with a detail fuel log over at least one OCI on dino and then the same fuel log on synthetic, we cannot have a meaningful discussion.


I disagree, strongly. We're talking about very small, incremental gains. No matter how detailed your logs, other variables are going to dominate the equation; temperature, wind, air density, traffic patterns, fuel quality. But just because you can't accurately measure it, doesn't mean it doesn't exist. It just means that the differences are small, and difficult to measure given the other variables.

Originally Posted By: KrisZ
In reality it’s the lighter oils that save fuel, not because the oil is synthetic.


Except that's not really true. It's been demonstrated that synthetic base oils have lower coeff. of friction, so viscosity isn't the ONLY variable that matters.

Originally Posted By: KrisZ
And even with lighter oil, the fuel saving can only be recorded in a lab, meaning the real world use will not see any measurable difference that wouldn’t be considered noise.


I don't really get this reasoning? Yeah, it's a very small, incremental gain. And yeah, it's within the noise of measuring via field tests. But how does that mean the effect doesn't exist? This just doesn't make sense. The lab is "real world". Less friction equals less energy expended, period. Just because the difference is small and difficult to measure in the "real world", it doesn't mean that the gains are any less "real world". It just means that they're difficult to measure given the other variables.

The common retort is something like "well, tire pressure matters more than oil viscosity". Well sure it does, but so what? Does that mean that any gains with a more efficient oil won't exist if I pump up my tires more or less? It's all additive, and oils which offer better fuel economy are just one (small) part of the equation.

Honestly, when the gains are this small, I'll take estimations based on lab reports over field tests any day of the week, unless you have an indoor track closed to all traffic and you're monitoring fuel quality.


"Honestly, when the gains are this small, I'll take estimations based on lab reports over field tests any day of the week, unless you have an indoor track closed to all traffic and you're monitoring fuel quality."

And my retort would be
"Torture numbers, and they'll confess to anything." Gregg Easterbrook.

The point is if I can not prove it but I have to go by the word of some lab and I can not compare the results myself and now your saying this is true because the gains are almost unmeasurable how can this be proved?