Bad gas mileage with M1

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Switched to M1 5w20 for this oci. My gas mileage has dropped by over 1 mpg and getting worse as the oil ages. Had been using Motorcraft 5w20 blend. I'm switching back.
 
Originally Posted By: oilchangeguy
Switched to M1 5w20 for this oci. My gas mileage has dropped by over 1 mpg and getting worse as the oil ages. Had been using Motorcraft 5w20 blend. I'm switching back.


What OCI's do you do?
 
OCI is about 4k. I keep very close eyes on tire pressure. Just seems like its the oil, I could be wrong. When I switch back MC, I'll know for sure.
 
Oh, and if you're dumping your oil and changing the filter ealier than you would JUST to get the M1 out, you'll be throwing the cost of those miles left in the OCI down the drain.
 
My truck will get better fuel mileage on MS5k or MSS than any other oil. people can choose not to believe me, however i drive the same route at the same time of day 6 days a week at the same pace checking every fill up. i will get .7-.8 mpg better with MS5k or MSS, i swear to it.


I love mobil 1 3 vehicles in my driveway have M1 5w30 in them right now, but honestly the fords ive owned including a supercharged mustang GT ran quieter and better on the Motorcraft 5w20 than M1 5w20.
 
Originally Posted By: donnyj08
My truck will get better fuel mileage on MS5k or MSS than any other oil. people can choose not to believe me, however i drive the same route at the same time of day 6 days a week at the same pace checking every fill up. i will get .7-.8 mpg better with MS5k or MSS, i swear to it.



I've seen a LOT of people make that comment about Super, you're not alone.

A lot of complaints about M1 and noise too...doesn't mean it's not working well but I don't like noise either. Rumor has it the AFE versions are quieter.
 
Originally Posted By: simple_gifts
Too many uncontrolled variables to conclude anything; tire pressure, atmospheric pressure, wind, fuel forumlation etc etc etc.


Exactly!

It's winter now...winter fuel formulation, longer open loop operation, more warm up time, etc...
 
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Originally Posted By: donnyj08
My truck will get better fuel mileage on MS5k or MSS than any other oil. people can choose not to believe me, however i drive the same route at the same time of day 6 days a week at the same pace checking every fill up. i will get .7-.8 mpg better with MS5k or MSS, i swear to it.


I love mobil 1 3 vehicles in my driveway have M1 5w30 in them right now, but honestly the fords ive owned including a supercharged mustang GT ran quieter and better on the Motorcraft 5w20 than M1 5w20.


My 5.4L doesn't seem to care what is in the sump
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I've run everything from D1 5w-40 to M1 5w20 in it (and a pile of oils in between, like Redline 5w-30, PC 0w-30, M1 AFE 0w-30 (current), AMSOIL AZO 0w-30, PC Duron-E 0w-40, M1 0w-40) with no discernible difference in fuel consumption.
 
When i had my ford escape, i could not measure any fuel mileage difference between 5-20, 5-30 and 5-40. So i don't believe there would be any fuel economy differences between brands of 5-20.
 
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There's so many variables in play, that I'm assuming you've neglected to isolate, that you can expect huge variations in mileage (+/-3MPG or even more), even with the same driving conditions and on the same oil.

Its entirely in your head.

I've had people claim after one tank of gas that they're getting "kick[censored] economy now" or "the worst I've ever seen". Or even better "the dashboard mileage thingy says its better."

Real science would dictate to average your fuel economy over an entire OCI to get a baseline, and calculate your standard deviation.

But realistically your standard deviation will show that your margin for error even exceeds 1 MPG, even over 5000 miles.
 
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On the 10w40 Maxlife the Clio is getting just under 58mpg.

I reset it once a month or so and the wife leaves the computer set to range to empty and usage is very regular.

Never noticed a drop in mpg in winter but this is the first time anything other than Mobil 1 0w40 has been in there in over two years.

This car was giving just over 60mpg prior to this OCI and the weather was cold then also.

I will be going back to Mobil 1 more than likely but will do some research before then.

Don't need to chnge the oil for 3k but i'm tempted to do an oil only change early.

My wife doesn't drive for economy in any way. Just gets in and goes.
 
Originally Posted By: oilchangeguy
Switched to M1 5w20 for this oci. My gas mileage has dropped by over 1 mpg and getting worse as the oil ages. Had been using Motorcraft 5w20 blend. I'm switching back.


oilchangeguy,

I use to get so so MPG (18-19) in my 01' Durango V-8 and then by accident I found out my last mechanic on the last major service did my tune up without cleaning the throttle body and changing the power steering fluid!

Since then I now take my truck back to the dealership for my services and had a good cleaning of the throttle body. On the highway the MPG shot up to almost 22.1 MPG!!!!

In addition those rats practically ruined my power sterring pump and was told the fluid was black and the entire unit was going south. This fluid was replaced too to my disgust.

Seriously, when was the last time you had the throttle body cleaned??? If not II'll just bet it needs cleaning and a new air filter.

Good luck

Durango
 
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