2013 Mazda 3 skyactiv mpg question, manual trans.

[DarkRyder]

i have recently purchased a mazda 3 skyactiv. rated at 38mpg on the highway i decided to put this to the test. i used cruise control to make sure that my speeds were as steady as possible and i got rather saddening results, tho cruise control could be the culprit. all tests ran on roads as level as possible.

55mph - 45-50 mpg
65mph - 40-45 mpg
75mph - 35-40 mpg
80mph - 26-30 mpg

cant anyone verify this?? at 80mph with cruise gave me horrible results. my old 08 mazda 6 could get low to mid 30's mpg all day long at 80. at near the same rpm if not lower on the skyactiv i take a hit on mpg, that doesnt make any sense to me..

 

[DKaz]

A good right foot will outdo cruise control. I never use cruise control unless my right foot needs a break for a minute. That said, your numbers seem inline with what I observe

At 35mph this morning, I observed 57-62 mpg on my Ultra Gauge. Too bad traveling long distances at 35mph isn't feasible. lol. At 50mph I go 47-53 and 45 I do 50-57.

 

[DarkRyder]

must be the gearing on this model then.

 

[DarkRyder]

think a CS SRI will improve the highway mpg?

 

[DKaz]

Maybe, but I only go 80mph once in a blue moon. I typically go 65mph at the most to save on fuel.

On a recent road trip, averaging 65mph on winter tires, I only managed to average 40mpg. In my Mazda 5 with the 2.3L engine and 5 speed manual, I managed to average 33mpg in the same conditions. But my 3 is way more fuel efficient in the city.

 

[DarkRyder]

i dont drive 80 very often either, but it just seemed weird that my mazda6 got better milage at 80 than the new skyactiv and they are turning almost the same rpms at 80.

 

[Suddueth13]

First off, are these just being observed via the info screen or actual useage based on fill ups? The info screen is nice to look at but isn't terribly accurate. Was your 6 the 2.3 or 3.0? Auto or manual? What RPM was it turning at 80mph? I assume your Skyactiv is the manual model based on the EPA number. It's turning close to 3000rpms at 80mph and wind resistance is exponentially higher than at 65mph. Do you expect it to achieve 38mpg no matter what speed you go? Doesn't really make sense to me. I got 39.8mpg last year on a trip to the beach with mine. It was 75/25% highway/city on that tank with mountains and frequent stops and accelerations during city driving. Only mod is Corksport cat back exhaust with racepipe. I regularly averaged 32mpg on my 8 mile trip to work which was speeds between 35-65mph. All of these numbers were actual useage averages based on miles driven to amount of fuel used.

 

[DarkRyder]

my mazda6 was the 2.3 w/ automatic trans. was turning close to 3k at 80mph same as the the 2.0 skyactiv is turning.

 

[DKaz]

My Canadian 2012 Skyactiv model didn't come with a trip computer (Weird... 2013s have them) but my Ultra Gauge is accurate +/- 2%. When recording my Fuelly, I always input actual litres of gas filled.

Peak fuel economy occurs between 25 and 35mph. Below that, rpms matter and above that, wind resistance matters. There were times when I did 80+mph as I was in a rush to get somewhere, in my Mazda 5, my old 91 Corolla, etc. I got terrible gas mileage all times.

Although I remember hearing that larger cars, especially ones with V6s, seems to be less affected by higher speeds for some reason.

 

[Suddueth13]

I could see you getting 30mpg with your 6 at 65mph or under but in no way would you get better than that at 80mph. The car was EPA certified at 28mpg with the automatic which is uasually based on 55-65mph averages. And again I'd like to see figures based on actual fuel usage versus just the display which is not accurate.