M1 0W30 ESP : High HTHS 3.5 Gas Mileage Shock

[ChrisD46]

After recent first time fill of M1 0W30 ESP I noticed no gas mileage hit at all in my suburban driving gas mileage (‘17 Hyundai Sonata 2.4L GDI) . Then yesterday I filled up with my usual top tier gas brand (ARCO) and immediately jumped on the interstate for a longish drive and gas mileage jumped up to a whopping 42 MPG (highest gas mileage ever in the Sonata !) Just sharing I thought by jumping up from a M1 5W30 EP HTHS 3.0 to the M1 0W30 ESP HTHS 3.5 that I would trade a higher HTHS for reduced gas mileage - but that has not been my experience at all. So far so good with this fill of M1 0W30 ESP in my ‘17 Sonata 2.4L GDI engine.

 

[BobsArmory]

Interesting, how could something like this happen?

 

[cheesepuffs2]

The Mobil 1 line just gets better and better.

I can't wait for Mobil 2: Attack of the Clones.

 

[Glenda W.]

All my vehicles but one are on ESP 0w30, it’s a great oil. I don’t monitor fuel mileage very closely, to many variables to attribute to oil.

 

[Patman]

Interesting, how could something like this happen?

It’s just one single trip here, so it’s not really an indication of anything. It could be slightly downhill or a tailwind.

 

[JoelB]

It's so interesting how people outside of the realm of science and engineering come to conclusions.

 

[dippschtick]

It's so interesting how people outside of the realm of science and engineering come to conclusions.

"Trust the science!"
"B-But, wait a minute..."

 

[edyvw]

Differences are usually miniscule to notice in regular driving.
But ESP 0W30 also meets the requirements of ACEA C2, which has higher fuel economy demands than C3.

 

[RDY4WAR]

Interesting, how could something like this happen?

It can't. There's not enough friction in an engine to make that kind of a difference. The oil would have to be a net power adder for that to happen.

 

[MrCoyote]

20kt tailwind with 3% decline

 

[Bullwinkle007]

I’ve noticed the difference to in my Acura MDX. 3.5L. It would avg 22 combined with M1 0/40 and the ESP 0/30 its between 22-25 now depending how much freeway.

 

[facility1]

the outside air temperature can and does make a difference, and driving into a wind too, as I doubt the oil can make that much of an increase in mpg.

 

[chris719]

It’s because every other variable swamps HTHS for normal driving. I get roughly the same mileage in my Mazda 3 with M1 0W-40 ESP X3 3.8 HTHS and the 0W-20 AFE.

 

[chris719]

I’ve noticed the difference to in my Acura MDX. 3.5L. It would avg 22 combined with M1 0/40 and the ESP 0/30 its between 22-25 now depending how much freeway.

Not really possible without controlling many other variables. Both of those oils have just about the same HTHS. Oils that are basically the same aren’t giving you 3 MPG. Maybe 0.3.

 

[ChrisD46]

Interesting, how could something like this happen?

I don’t know either ? The same could have happened with a number of good oil brands of 5W30 . I only wanted to emphasize do not be worried that your gas mileage would severely drop by moving up to a higher HTHS 3.5 oil from Mobil or other oil brands offering a HTHS 3.5 oil . In my case , I’ll keep using M1 0W30 ESP and my local WM sells a ton of it . After my next 3,500 mile / 6 month OCI I’ll get a UOA done to see how the oil looks in this Hyundai 2.4L GDI engine .

 

[tbm5690]

After my next 3,500 mile / 6 month OCI I’ll get a UOA done to see how the oil looks in this Hyundai 2.4L GDI engine .

Why that often, especially with ESP?

 

[Bullwinkle007]

Not really possible without controlling many other variables. Both of those oils have just about the same HTHS. Oils that are basically the same aren’t giving you 3 MPG. Maybe 0.3.

I’m just going by what the ecu says. I don’t actually calculate miles to how many gallons

 

[melk]

exactly. track the actual miles driven and divide by the actual gallons of gas at next fill up.

watching the onboard display is fun amusement, but that's all it is.

 

[Patman]

exactly. track the actual miles driven and divide by the actual gallons of gas at next fill up.

watching the onboard display is fun amusement, but that's all it is.

My onboard display in my Civic is only off by 1MPG so that’s close enough. The main thing is that it’s consistent so I can see if it ever goes down a lot and then I can see if there’s a problem that needs addressing.

Perfect example of this is with my girlfriend’s RAV4 hybrid. She got it in March 2024 and we have been paying attention to what the onboard display says, and it was consistently in the 7L per 100km range until she started using the AC in the summer and it went up to 8. Now it’s her first winter with it and it is consuming a lot more for her, it has been around 10L per 100km. It turns out that in this colder weather she has been often sitting in the car waiting to pick up her kids (she’s got 3 kids and does a lot of mom taxi duties) and she leaves the car on so the ICE keeps cycling on and off (mostly on) to keep warm. So I told her that is the reason why her economy has been so bad! So she has cut back on that practice and now it’s back down around 9L per 100km. I know this turned into a long winded story but my point is that the reading for the fuel economy can definitely be useful!

 

[Jetronic]

Interesting, how could something like this happen?

Higher HTHS will increase friction everywhere and every time the engine was in full hydrodynamic lubrication, but it will reduce friction where it wasn't. so it would be case to case dependant if you see an imrpovement, reduction or no difference in mpg. And it could swing one way on a certain route, and the other way on another.

But the differences would be small, very hard to detect. we're certainly not talking about 10% better or worse economy, more like 1%, so going ftom 25mpg to 24.75 or 25.25.... I don't know how to attribute such a change to oil viscosity though.