Why did I pick up 1.8mpg going to a higher viscosity oil ?
- Thread starter Camperguy
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How does your engine know the oil is about to be changed? Do you talk out loud to yourself? Does it know when you stop by the auto parts store and pick up oil and filter?
You more than likely have "anything goes" fuel that still has butane in it. Not enhanced RVP for winter and not reduced for summer. Hint, now is a great time to fill your fuel stash as it's typically a pretty cheap time of year.
The reduced drag of thinner air combined with a lack of need for HVAC really helps.
The reduced drag of thinner air combined with a lack of need for HVAC really helps.
Better ring seal and warmer temps....summer gas
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Every engine has an optimum viscosity where friction, ring seal, top end, and bottom end lubrication are balanced at operating temp. At this point, using either a lighter or heavier oil than optimal will reduce performance.
It’s entirely plausible that moving from a lighter oil to a heavier oil could move up this curve and hit this optimal point. The driving factor here would likely be ring seal. Whether this could achieve a measurable 1.5 mpg increase is debatable, but it is a real phenomenon.
It’s entirely plausible that moving from a lighter oil to a heavier oil could move up this curve and hit this optimal point. The driving factor here would likely be ring seal. Whether this could achieve a measurable 1.5 mpg increase is debatable, but it is a real phenomenon.
Likely due to weather shifting and gas going to summer blend
Beat me too it. This.
It's always a combo of factors.
There could be a little better ring seal, but detectable as delta MPG? I dunno.
Any perceived MPG gains or losses are all in your head. If the mechanic notices it then it is all in his head too. If the fuel manufacturer claims it so then it is all in their head too. If the vehicle calculates it then it is all in the computers head too. Nothing can be discerned without length quantitative analysis and adjustment for controls. Please provide your methods, data, and statistical modeling for prompt and rigorous peer review. Just a placebo effect otherwise. All an illusion.
But in this case they are in his head, at least of sorts. I don't care how many prognostications one can concoct about "ring seal" and other ideas, you don't gain 1.8 MPG when going up two grades.
Nor is anyone making a definitive measurement that isolates the singular variable of the oil in everyday driving. No way, no how. Just because you observe something doesn't allow you to assign that observation to any variable you imagine it may apply.
New filter ..... different media.
You just got a filter with media which is easier to pump oil through.*
* I am kidding
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“Prognostication”? Who is predicting the future?
Why the quotations on ring seal? Do you disagree that going with a heavier viscosity can measurably improve engine performance by improving ring seal? This has been tested in controlled environments. The info is out there.
Agreed. There’s no way to attribute cause here with any certainty.
Condemning without data or analysis is a different side of the same coin as confirming without data or analysis.
But at least I have basic physics on my side. Automakers are reducing HT/HS for a reason, and they aren’t increasing it for the same reason.
If the op's vehicle is saying his mileage has increased, how can anyone say it's all in his head ?.,,
Because he’s saying it’s due to increasing the oil grade. It’s not the observation that’s disputed it’s the cause. Two very different things.
No one is saying it didn't.
Everyone is saying not from the oil alone. Many factors/variables.
Some debate if the oil is a factor.
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It’s why the words “likely,” “unlikely,” “plausible,” and “implausible” exist.
Is it likely? No. Is it plausible there could be a positive effect? Yes. If it exists, is that effect the primary driving variable? Not likely.
I change the oil every 4-5k miles. I drive the same trip every day. Live in Southern AZ. This time of year I drive with the windows open. I actually pick up about 2 mpg in the summer with the AC on. 80% of my driving is 50-60 MPH on long stretches. I get about 18 mpg on the highway 75 MPH. This is AZ it's pretty much windy all the time. I have always monitored my mpg on every tank of gas in every vehicle I've owned. If I wasn't obsessive compulsive I wouldn't be on an oil forum 
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