The rare case of synthetic oil

[Explorer75]

I always use 5w-20 Motorcraft Blend, decided to try the Motorcraft full synthetic. Surprise, I feel less power, specially in low rpms, fuel economy is worse, at least 1 mpg.
I have no scientific explanation, just day to day driving habits under same conditions and feeling (butt dyno). Did a search and there are a couple of other forums where people had actually felt this.

 

[Mbrooks420]

It’s most likely something else. (Like winter blend fuel) Your change of oil didn’t net a MPG loss, and make less power.

 

[Odrapnew]

I agree with Mbrooks420, changing to synthetic is not likely the cause of power or fuel economy reduction....unless you changed oil weight.

 

[Explorer75]

I'm just theorizing, what if the oil pressure is dropping, just borderline of the minimum and no check engine.Full synthetic is thinner than blend, that would affect oil pressure in my oponion. How can I monitor oil pressure?

 

[Mbrooks420]

You can install a mechanical (or electric sending unit style) gauge. That’s the on my sure way to know.

Lack of oil pressure won’t set the CEL. It’d light the “check gage” light.

How many miles on the motor?
(Synthetic oil won’t lower pressure)

 

[Explorer75]

You can install a mechanical (or electric sending unit style) gauge. That’s the on my sure way to know.

Lack of oil pressure won’t set the CEL. It’d light the “check gage” light.

How many miles on the motor?
(Synthetic oil won’t lower pressure)

96,000 but mainly city driving.
Tomorrow I plan to switch back to 5w-20 blend and monitor fuel economy.

 

[1991 sploder]

Yea but the synthetic blend could be more slippery than the full synthetic.... I could totally see that being the case seeing as only viscosity is measured not lubricity. Synthetic oil uses smaller particles and hence closer metal on metal contact compared to conventional.More "slippery" oil will give more power for sure. I'm sure when you blend the two that's where the magic happens.

 

[Mbrooks420]

Oil doesn’t work like that. If blend was somehow magical and “slipperier” there’d only be blend.

The blend change will be nothing but a waste of good oil.

 

[1991 sploder]

Oil doesn’t work like that. If blend was somehow magical and “slipperier” there’d only be blend.

The blend change will be nothing but a waste of good oil.

Yea right why do u think they have synthetic blend? Because that's the sweet spot umm no no no it does work like that.

 

[jpz]

Yea right why do u think they have synthetic blend? Because that's the sweet spot umm no no no it does work like that.

Blend was created to get some of the benefits of synthetic without the full purchase price of synthetic.

I agree with many of the above posts, going synthetic will not decrease HP or MPG. There is something else at play here. You can never rule out the placebo effect.

 

[Explorer75]

Well, went back to Blend 5w-20, believe it or not power is good again and mpg are normal again. No placebo effect, 100% sure of that.
For those worried about the oil I took out, I recollected in a clean container and plan to just give it to someone that uses 5w-20.

I´m sure there is a technical explanation, hopefully is not oil pump related or something clogged, you name it. If the truck likes blend, blend it will get.

 

[03WIExplorerLtd]

Well, went back to Blend 5w-20, believe it or not power is good again and mpg are normal again. No placebo effect, 100% sure of that.
For those worried about the oil I took out, I recollected in a clean container and plan to just give it to someone that uses 5w-20.

I´m sure there is a technical explanation, hopefully is not oil pump related or something clogged, you name it. If the truck likes blend, blend it will get.

If.you just changed today how do you know MPG are back to normal?

 

[Explorer75]

If.you just changed today how do you know MPG are back to normal?

Changed it, went for my usual drive. Power feels normal, mpg are back up about 2. Throttle response is better. I do a 1 hour drive almost daily, same route. Traffic is usually the same (light), try to obey speed limits, don´t race the engine, etc.

 

[Mbrooks420]

You can’t track mileage in such a short time. To get an accurate number you need to track mileage over TANKS of fuel. Way too many variables. NO oil of the same weight would net a 2 mpg gain. That’s more than 10% of your mileage.

 

[Odrapnew]

If you can feel the difference in power between different engine oils, you must have the most advanced 'butt dyno" ever.

In the Explorer, I bet there's less than 5hp difference between the worst conventional oil and the best oil there is (assuming same viscosity).

 

[Explorer75]

You can’t track mileage in such a short time. To get an accurate number you need to track mileage over TANKS of fuel. Way too many variables. NO oil of the same weight would net a 2 mpg gain. That’s more than 10% of your mileage.

Yes I agree I didn´t do a very technical measurement of the MPGs. I do feel and see the difference in the onboard computer. I apologize, I´m not tying to be an a$$ or complicate things, if by any chance someone feels I´m just bored or crazy. Just a real world observation of how the truck feels with one oil or another. In this case it isn´t that the Blend gives me 2 mpg over the synthetic, the way I see it is that for some mechanical reason when I used the synthetic I lost power and fuel economy. If I had only lost fuel economy I would think the usual variables: fuel, air temp, traffic, speed, driving style, but I also felt loss of power and throttle response, vehicle felt "heavier" or slower to respond. Now is peppier like before, more sensitive to the accelerator.

Again I´m not trying to impose nothing, this is my perception, just wanted to share it in case someone had the same experience.

 

[Explorer75]

If you can feel the difference in power between different engine oils, you must have the most advanced 'butt dyno" ever.

In the Explorer, I bet there's less than 5hp difference between the worst conventional oil and the best oil there is (assuming same viscosity).

I´m sure that besides my butt dyno there is some technical explanation about my engine, as I said before. I agree 5 hp is impossible to notice. I would think there´s got to be at least 10 to 15 hp difference for anyone to notice.

 

[1991 sploder]

Right on so like a less than 5hp gain and less than 2mpg gain but still, nobody can claim 0 effects can they?

 

[Odrapnew]

Thinking about the mechanical side of things, I don't think there would be any measurable difference just due to friction alone.
I guess that's what I was originally alluding to, not thinking of other components.

What about the other things that utilize oil circulating through the engine?
Maybe the cam phasers are not reaching optimal position with the synthetic? That might set off a check engine light, but maybe not.

Just tossing out ideas.

 

[peterk9]

FWIW;
The simplest change to make regarding improved powertrain efficiency is to switch to a synthetic engine oil at your next oil change service. Independent test data commissioned by Royal Purple synthetic oil shows that just this change can improve fuel economy 4.5 percent.

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Peter