First oil change with the new Mazda 0w20 GF-5 with moly - Improved MPG

Hi guys, I just changed the oil my self at 5k miles with the new Mazda Genuine GF-5 0w20 with Moly and I got improved gas millage. I am not sure if it is because it is first oil change (e.g. factory oil thicker?, different?) or its a result of the new oil (I believe that) but I immediately got improved gas mileage. Before I announce the numbers need to say that it is the Sport Manual (so you don't get shocked).

Before: 60 mph ~37-38 mpg, 65 mph ~ 34-35 mpg (50 miles highway, cruise control)
After: 65 mph ~40 mpg ( (50 miles highway, cruise control).
It is exact same route. First day after the oil change I though it might be a reversed wind, so I waited a few more days. Same results both direction (e.g. not downhill/uphill effect). This is in Chicagoland.

When I mixed it with some city driving (more like suburban driving) I currently have it on 37 mpg avg with ~40 mph avg speed. I should also say that I have about 100 pounds weight in the trunk at all times.
I am just blown away from this vehicle. I used it for business and thanks God I did not buy some heavy burner so called "truck".
I hope this tech is also reliable! Thank you Mazda!

P.S. Someone please confirm if you have similar results after the first oil change with different brand oil.

EDIT: For those unaware, this oil has perfect characteristics. Here is a detailed information about is. That is the reason to chose it. I had some hard time finding it with local dealerships for a price under $8 a quart. Currently, ROTO in Arlington Heights should have a case and should be able to sell to you for $8 (or less) if you get a dozen. You can also order onlie - the cheapest places I found is HandAaccesories (google it) ~$6.50 a piece + $20 shipping for a dozen and Arlington, VA Mazda (just a bit more, but if you live there you can pick it up and save the shipping cost).

UPDATE:
Almost a month later and I will have to disappoint you. I never managed to repeat those "crazy" numbers posted above: same route, similar conditions, same gas stations, same speeds. However, the week I got those ~40mpg numbers was very warm 70+ F. Since then, it has been always cold - under 45 F. My conclusion is that the car generally burns more fuel when its called outside. And while this will be no surprise for short city rides, I can not explain why it is happening on long highway trips (50-60 miles). And by that I mean a difference of 2-3 mpg on the current fuel gauge, and so the average (my car stays in a garage and I start and go - no warm up idle. In addition the highway entrance is 1.5 miles away). Could the heater ( I keep the interior pretty hot) be the reason?
Overall, it still has better fuel economy with the new oil, but difference is not as much as I though.

UPDATE 2

Just a quick update after 2 years (55k miles on the car):

I did put Castrol 0w-20 (It was super cheap at Walmart) in the fall of 2014 and definitely the car burns more fuel this Winter. Anywhere from 1-2 MPG difference.It fall down to 29MPG which is the first time I am seeing this. Previous winters it was 30-32. Summer 33-35.

my mpg stay pretty constant since new (unless I'm having too much fun or the tire pressures get a bit low). I noticed a jump in zip after a thousand miles or so. I currently have Castrol Edge in mine but now have a case of Mazda oil waiting for the next oil changes.

Too many other variables involved to be a meaningful change in fuel economy due to oil (including driving conditons, driving technique, engine break-in, fill technique, weather, fuel blend, etc.).

CX-SV said:

Too many other variables involved to be a meaningful change in fuel economy due to oil (including driving conditons, driving technique, engine break-in, fill technique, weather, fuel blend, etc.).

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I understand that, but that happened the next day I changed the oil and it is a significant difference (3-4 mpg +). It has been the same for 250 miles. I check my mpg values hourly and there was definitely a change. What I don't know for sure is if it was from the special oil or because the original oil had something in it to help the engine break in. Will be reporting back with more statistics.

BGChicago said:

I understand that, but that happened the next day I changed the oil and it is a significant difference (3-4 mpg +). It has been the same for 250 miles. I check my mpg values hourly and there was definitely a change. What I don't know for sure is if it was from the special oil or because the original oil had something in it to help the engine break in. Will be reporting back with more statistics.

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I'm interested in seeing your stats after more driving. I did my 1st oil change using Mazda Oil and noticed no difference. Additionally, did you have any trouble replacing the little aluminum ring? I'm coming up on my second change soon and could use a pointer on this. I prefer changing it myself, but Mazda's oil was much cheaper than the local store's. Let us know what your mileage is after some time!

I am about to get my first oil change (Schedule 1) and had to look for a dealer that has this oil in stock, I will let you know my results as it is about a 50 mile drive to that dealer. My local dealer looked at me like I had a second head when I asked if they have that oil, then sent me to parts where they said I would have to order a case to get it in. The parts dept had not even heard of the new oil...... Not a lot of confidence in my local dealers service center at this point. How would a Mazda dealer not get an update when a new oil is specifically designed for the SKYACTIV engines?

CodyZoom what kind of the Mazda Oil did you use (part number) this new oil is only apparently out a couple of months....

ReManG said:

I am about to get my first oil change (Schedule 1) and had to look for a dealer that has this oil in stock, I will let you know my results as it is about a 50 mile drive to that dealer. My local dealer looked at me like I had a second head when I asked if they have that oil, then sent me to parts where they said I would have to order a case to get it in. The parts dept had not even heard of the new oil...... Not a lot of confidence in my local dealers service center at this point. How would a Mazda dealer not get an update when a new oil is specifically designed for the SKYACTIV engines?

CodyZoom what kind of the Mazda Oil did you use (part number) this new oil is only apparently out a couple of months....

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I cant speak for CodyZoom, but I'm about to use Mazda Ow20 with Moly on my first oil change (3000 miles). I ordered it online, didnt even bother seeing if the local dealership had it.

Oil goes through a lot of stress and, synthetic oil or not, the additives definitely wont last. An oil change will definitely help. If it didnt, we would never change our oil. The engine will just operate more efficiently on a fresh fill.

BGChicago said:

I understand that, but that happened the next day I changed the oil and it is a significant difference (3-4 mpg +). It has been the same for 250 miles. I check my mpg values hourly and there was definitely a change. What I don't know for sure is if it was from the special oil or because the original oil had something in it to help the engine break in. Will be reporting back with more statistics.

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I'm seeing the same thing, sport manual here too. I have just over 7000 miles on my car. I did my first oil change myself at 2000 miles, probably unnecessary as the oil looked very clean, but it cant hurt. I used 0w-20 Mobil 1 with a Bosch 3330 filter. The Mazda dealer in my town gives you free oil changes and tire rotations for life. I needed my tires rotated and would save myself $50 on oil and filter and anyways. I always reset the MPG and MPH averages with every fill up and had only driven 35 miles on that tank before it had the oil change. I have NEVER seen mpg this good. I was thinking that I got some really good gas without any ethanol, but they add MORE ethanol in the winter, not less. The other thing I considered was that they may have updated the ECU programming while the car was in the service dept. at the dealer. I will check the ECU with my ODBII scanner to see how many miles its been since the last reset, but I doubt they did an oil change, tire rotation, washed the car, and re-flashed the ECU in an hour and a half.

My dash usually shows 28.5 mpg with an average speed of 24 mph. It is now showing 32.1 MPG with an average speed of 24 MPH. I am also running 91 octane fuel exclusively since I dont mind spending 2-3 dollars every two weeks to get better mpg and performance. With all other things being equal, this new Mazda oil must be whats making the difference. I would have never expected the difference to be this large however. Overall this car is amazing. I was completely satisfied before, but this is just icing on the cake getting over 30 mpg around town in a car this size. Im sold on using the new Mazda oil at this point, even more so that the dealer gives it to me for free.

I went to the local Mazda dealer and bought the synthetic oil they do the changes with. It was "mazda" brand oil. They also had the aluminum washers for sale. I'll have to double check on the exact part number since that was 4300 miles ago, but it's whatever they use for their CX-5 oil changes.

I just got the oil changed with the 0W20 MQ (molybdenum) oil and will keep up with my mileage to see if there was a difference. I am changing my oil on the Schedule 1 (7500 mile) interval. Dealership saved me a used oil sample and the old filter, I will cut that apart for my own curiosity.....

http://www.cleanmpg.com/forums/showthread.php?t=45295

http://m.mazdaforum.com/forum/showthread.php?p=133228

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2781625

I will post the rolling three tank average when I get it, but as for now, on the current mileage gauge, I am up 2-6MPG (current MPG reading) from where I was for driving my daily road during the various cruise portions.

I have one section of road I travel daily that is just over one mile long, it is parallel to a railroad siding and as flat as I can find on my route. Previously at 50mph with the cruise control on, the current MPG reading was ~35MPG with no wind when I drove this section on the way to work. The last three days the current MPG reading was ~40MPG for the same stretch. As there is very little traffic on this section, I can get to speed and set the cruise with little worry. I generally use the morning drive for this, but checking on the way home (warmer) the MPG is still at or above 40, incredible (I actually turned around and drove it two more times this afternoon).

I will update this thread when I have the fill up from the first tank (same pump, same station), and the average from the last three after I copy them from my phone. My average MPG gauge has risen by 2MPG for this tank from the last tank (reset between tanks) prior to the oil change during the 100 miles I have driven so far with the new oil. I know this is a small set of data, but the results I have seen will be positive if this continues. I never would have thought the type of (same weight) oil would affect MPG this much in an already efficient vehicle.

I've noticed with both of our cars, the mileage tends to drop as the oil ages (always in that 2-3 mpg). Then I get a healthy spike when the oil is changed, only to observe the same downward cycle.

I just changed my oil from the Mazda oil to Mobil 0W-20W and my mileage is about the same as it was before.

PhoenixINX,

I agree, I had a flat run though on my mileage for the last 3000 miles I drove until the oil change. The previous 4500 miles had shown a lower MPG average for that time, and it settled at around 29MPG, then the last 3K miles before the oil change it was around 30MPG, most likely from driving habits/break in complete/routine established, etc. I will keep the averages like I did until my first oil change and then let you know for longer term as well. I have never had this kind of increase when the oil was changed however, that is what suprised me. I figured at the cost of the oil, it was worth a shot and took it, if it does not work out, oh well. This oil is engineered for the SKYACTIV engine, but I would have used castrol, mobil, penzoil, etc otherwise if I had not heard about it.

Last three tanks PRIOR to oil change with Mazda MQ oil (factory fill)- 29.6mpg over 352mi / 30.1mpg over 328mi / 30.9mpg over 356mi for a total of 30.2mpg over 1036 miles.....

First tank AFTER oil change with Mazda MQ - 31.4mpg over 318 miles = +1.2mpg for this tank and a rolling three tank average of 30.8mpg over 1002 miles, up 0.6mpg for the three tank average.

So far, this is looking very interesting, I will update as I fill up, over time the numbers will show any trends....

Second fill up after oil change with Mazda MQ oil = 35.20mpg over 377 miles / +3.8 MPG over last tank (less holiday shopping too)

Three tank average with this one is 32.5mpg over 1060 miles = +1.7mpg from last three tank average or +2.3mpg on three tank average from factory fill oil.

So far I have been impressed, but I will wait and see for further numbers until I am convinced. My ROI on this oil for the price difference is about +1.5mpg, so it is looking like I may use this oil for the next change as well if the numbers hold up. I am driving the same route every day during this evaluation, and I believe the first tank after the oil change took a hit with the holiday shopping being more city driving. Normally about 80% HWY/ 20% City. My Average MPG reading was under reporting for the first time on this tank, it showed 33.6mpg at 41 mph average speed.

Very interesting results. I'll be trying the Mazda Moly oil when the time comes.

I think fuel can make quite a difference with such a high tech engine. I've been running Chevron because it's the cheapest fuel in my area but on Christmas Eve I decided to fill up so I wouldn't be looking for an open station on Christmas Day and I filled with Union 76. My MPG on the trip computer almost immediately climbed to a range I was not familiar with (35-36 mpg). By the time I was ready to fill again it said 35.3 mpg but my manual calculation confirmed 36.3 mpg! These are really good numbers for AWD and automatic tranny. Imagine the mpg numbers I'll get when I switch to moly!

One complicating factor was that I had just recently added 2 lbs. of air to each tire. I'm now running 37 psi in my winter tires.

I agree, and I have been using Shell 87 octane, from the same station, a fairly high volume one. I would say that 85% of my fill ups have been at this station, and on this little endeavor, I will try to avoid switching fuel stations for another tank, just to minimize variables. I am thinking of running my all seasons at 40-42 psi after this to see what effect that would have, and to judge the ride as well. I am currently running 36 psi cold on them, I tried 38 psi and there seemed to be more road noise.....

Whenever my tires have gotten a bit low I've noticed a drop in mpg. And although I haven't filled up at the same place enough to find a pattern I have also noticed differences after getting gas from different companies. But there were too many variables to tell anything definitive. I'm guessing as we get cars that push more and more of the limits of efficiency it takes less and less to affect them noticeably.
The biggest boost to mpg I've found is getting stuck in traffic that is flowing pretty steadily at 55-60 mph

http://mazda.handa.com/cx5.html

V8toilet said:

I just changed my oil from the Mazda oil to Mobil 0W-20W and my mileage is about the same as it was before.

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Are you really located in Massachusetts? The Mobil one is significantly thicker specially when cold (I think its the thickest 0w20 on the market) so you should definitely see some improvement with the Mazda GF-5.

There is no guarantee that your original oil was the same GF-5. As far as I know, this oil was not available even in bulks till early summer. Even the manual recommends Castrol Oil which means Mazda did this deal with Idemitsu late. Otherwise, why wouldn't they recommend their branded product? So most likely, the first 3 months of production had different type of oil.