Semi-Silly question... MPG vs Mode?

[DBM-Red-G2706]

Just out of curiousity...

99.9% of the time I put my 2016 GT350 in Sport Mode, I just like it better, sound is better, suspension, etc...

BUT I pulled out of the garage to drive to work recently very early when my wife was asleep, so I left it in Normal mode and drove to work. It was fine, less satisfyingthan Sport mode.

Here's the thing. It seemed like I got WORSE MPG than the other times I drove to work in Sport mode. I made sure to drive home in Sport mode and still that was my impression.

So... Do we get different MPG in different modes and how does that map out?

Thanks in advance.
David

Sponsored

 

[Pony2015]

My two cents: Assuming you are reasonably within the torque band (ie, ECU is not retarding spark to prevent knock), the more times you need to rotate the crankshaft to go some distance x, the more fuel you use. This is because at higher RPM, there is more friction in the engine, including from the oil. Likewise, very hard acceleration wastes fuel because engine runs a rich mixture to keep temps down and prevent knock (you will know this because the cat will glow along with the smell of unburnt fuel). Accelerating too slowly also wastes fuel as you are taking too long to get to a more efficient higher gear. Optimal mpg requires brisk (not hard) acceleration combined with short shifting at around 2,500 rpm (no one actually does this, because no fun!) This is all easily tested with a manual transmission by resetting the trip meter and watching mpg for various styles.

Now, the various modes on an automatic make adjustments to how shifts are done to favor a particular driving style, but they do not enforce it -- you can still override by how hard you get on the accelerator. So it is still possible to get worse mpg in normal mode with more aggressive acceleration compared to sport mode with less aggressive acceleration (or taking too long to get to high gear in normal mode relative to sport would also do it).

 

[engineermike]

The only thing in the engine tune affected by drive mode is pedal torque response (how much torque is requested ant a given pedal position) and active exhaust position.

 

[NightmareMoon]

The only thing in the engine tune affected by drive mode is pedal torque response (how much torque is requested ant a given pedal position) and active exhaust position.

Right, so its not a big factor in your mpg over any sort of sigificant distance.

 

[DBM-Red-G2706]

I suspected it was Operator error...

 

[CrazyHippie]

I would venture to assume that Normal mode will provide the best fuel efficiency if you're able to drive it in a manner that maximizes mileage. In other words, Normal probably offers the ability to achieve the best mileage. Normal mode was likely programmed with EPA standards in mind.

I'm able to run in the 22-24 mpg range on a long (600 mile) highway trip that I do several times per year in Normal mode. I'll make a point to run the same long trip in Sport mode next time to see if there's a difference.

 

[CrazyHippie]

Ok. I've now done my usual trip in Sport Mode. No difference in gas mileage. It makes sense, though - the majority of the trip is highway driving.

 

[sirben711]

My two cents: Assuming you are reasonably within the torque band (ie, ECU is not retarding spark to prevent knock), the more times you need to rotate the crankshaft to go some distance x, the more fuel you use. This is because at higher RPM, there is more friction in the engine, including from the oil. Likewise, very hard acceleration wastes fuel because engine runs a rich mixture to keep temps down and prevent knock (you will know this because the cat will glow along with the smell of unburnt fuel). Accelerating too slowly also wastes fuel as you are taking too long to get to a more efficient higher gear. Optimal mpg requires brisk (not hard) acceleration combined with short shifting at around 2,500 rpm (no one actually does this, because no fun!) This is all easily tested with a manual transmission by resetting the trip meter and watching mpg for various styles.

Could be this.

I know that my 'normal' mode not only feels slow, but also draggy. Like my breaks are sticking on. I find that sport mode lets me get up to speed more easily (less throttle) and lets me get into a higher gear faster to coast in.

Sponsored