Sport vs Eco mode (mpg)

[KegsBdry]

I've mostly been driving around in Normal or Sport mode, rarely Eco mode. Because why buy a 400HP machine and not use it?!

But I had to drive family around and I wanted them to have a comfortable ride. So I switched to Eco mode for a couple of gas full ups.

I have been getting around 16-17 mpg for Normal/Sport mode, but Eco has been 22-23 mpg. Is it really that big of a difference?! It seems like a huge difference to me considering I had 3 extra people in my car that whole time. Maybe when I'm in Sport mode I hear the engine (fake noise) and it drives me to be more of a lead foot? I don't know.

Is everyone else getting big differences between Normal/Sport and Eco mode?

 

[2020FordRaptor]

Sport mode keeps the gearing longer. For example it shifts in 3rd gear at 3k RPM and at Eco it shifts in 3rd at 2k RPM. I always kept ours in Sport because I liked the downshift and the way it drove.

 

[Stone17]

The A/C will turn down in Eco Mode.

 

[2020FordRaptor]

The A/C will turn down in Eco Mode.

Really? I didn't think so.

 

[Big Turk]

Really? I didn't think so.

I drive in eco mode most of the time on the freeway and I have not noticed a drop in AC. I haven't been specifically looking for it either though.

 

[Big Turk]

The owner's manual only specifies that electric steering, stability and traction control, throttle control, transmission shift schedules, and four-wheel drive can be changed due to a drive mode selected.

 

[st8]

Guessing you’re just staying out of boost. Thereby less fuel being used. I’ve never tried exclusively driving in eco for a full tank so not sure really.

 

[2020FordRaptor]

Guessing you’re just staying out of boost. Thereby less fuel being used. I’ve never tried exclusively driving in eco for a full tank so not sure really.

Boost does not effect gas mileage. It actually helps it. Technically when you accelerate faster the turbos spool more. If you don't they don't spin as fast. Turbos go off the exhaust and not the engine like a supercharger.

 

[st8]

Boost does not effect gas mileage. It actually helps it. Technically when you accelerate faster the turbos spool more. If you don't they don't spin as fast. Turbos go off the exhaust and not the engine like a supercharger.

Okay well I stand corrected. My understanding was more boost= more air flow = more fuel. But I could be terribly wrong lol

 

[2020FordRaptor]

Okay well I stand corrected. My understanding was more boost= more air flow = more fuel. But I could be terribly wrong lol

No it goes: more acceleration = more gas = more exhaust = more turbo spool

 

[st8]

No it goes: more acceleration = more gas = more exhaust = more turbo spool

Okay yeah that makes sense.

 

[Stone17]

I drive in eco mode most of the time on the freeway and I have not noticed a drop in AC. I haven't been specifically looking for it either though.

Check it out. It lower down the fan speed in Eco Mode.
I had the A/C set to Auto and LO.

 

[2020FordRaptor]

Check it out. It lower down the fan speed in Eco Mode.
I had the A/C set to Auto and LO.

Oh you had it on Auto. That makes sense then.

 

[TMac]

Boost does not effect gas mileage. It actually helps it. Technically when you accelerate faster the turbos spool more. If you don't they don't spin as fast. Turbos go off the exhaust and not the engine like a supercharger.

I don't know where you heard this (or why you'd post it) because it is absolutely not true as it pertains to MPG. In fact, it's so misinformed that it almost pains me to have to chime in on this!

Gas mileage is directly related to BSFC- brake specfic fuel consumption- which is the amount fuel it takes to make one HP at various load and RPM, but in no case is it impacted by "more exhaust' or "more spool". That type of thinking also forgets auxiliaries like oil pumps, water pumps, mechanical friction, etc. The MPG expenses of which increase at a square of the RPM. Not to mention the fact that during any type of boost condition the ECU is likely to command a higher than stoichiometric fuel ratio- meaning it will be rich (more fuel). That is NOT a MPG savings.

If that thinking were correct, we wouldn't bother with 10 speed overdrive transmissions in an attempt to utilize the lowest possible horsepower and RPM required to drive the vehicle. We'd just drive around in "boost" making far more HP than necessary. Surely anyone can see that the more HP you make, the more fuel it requires.

Certainly peak BSFC generally happens at peak torque- turbocharged or not, but that small increase in inconsequential to generating only enough HP to drive the vehicle at a given speed.

 

[2020FordRaptor]

I don't know where you heard this (or why you'd post it) because it is absolutely not true as it pertains to MPG. In fact, it's so misinformed that it almost pains me to have to chime in on this!

Gas mileage is directly related to BSFC- brake specfic fuel consumption- which is the amount fuel it takes to make one HP at various load and RPM, but in no case is it impacted by "more exhaust' or "more spool". That type of thinking also forgets auxiliaries like oil pumps, water pumps, mechanical friction, etc. The MPG expenses of which increase at a square of the RPM. Not to mention the fact that during any type of boost condition the ECU is likely to command a higher than stoichiometric fuel ratio- meaning it will be rich (more fuel). That is NOT a MPG savings.

If that thinking were correct, we wouldn't bother with 10 speed overdrive transmissions in an attempt to utilize the lowest possible horsepower and RPM required to drive the vehicle. We'd just drive around in "boost" making far more HP than necessary. Surely anyone can see that the more HP you make, the more fuel it requires.

Certainly peak BSFC generally happens at peak torque- turbocharged or not, but that small increase in inconsequential to generating only enough HP to drive the vehicle at a given speed.

If you'll see my above post it explains why I said that:

more acceleration = more gas = more exhaust = more turbo spool

 

[TMac]

Boost does not effect gas mileage. It actually helps it.

This is what you wrote. It's nonsense.

more acceleration = more gas = more exhaust = more turbo spool

Ummm, yes, but what does that have to do with gas mileage?

 

[2020FordRaptor]

This is what you wrote. It's nonsense. Ummm, yes, but what does that have to do with gas mileage?

I'm saying turbo spool doesn't hurt gas mileage, harder acceleration does. When going up a hill with cruise control on in 10th gear, the turbos feed the engine, and helps the engine breath better, therefore better gas mileage.

 

[TMac]

I'm saying turbo spool doesn't hurt gas mileage, harder acceleration does. When going up a hill with cruise control on in 10th gear, the turbos feed the engine, and helps the engine breath better, therefore better gas mileage.

And you base this on what theory? Really, I'm not trying to single you out, but you have no idea what you're talking about. When ascending a hill, the load increases. As load increases, so does the exhaust cycle pressure- that increase in pressure causes an increase in turbine speed. To maintain the same speed, you have to increase the amount of horsepower requiring more fuel. Increasing the load has the same effect as increasing the acceleration- thus negating your whole statement. It doesn't have anything to do with helping the "engine breath better". Its breath is bad enough!

 

[SimonsGTS]

Making the engine breathe better increases the VE (Volumetric Efficiency), but the more air required equals the more fuel that will be injected to maintain stoichiometric AFR (Air Fuel Ratio). So additional loads like climbing a hill or carrying additional weight will require more fuel and that will not increase fuel mileage. So spooling up the turbo will increase the engines efficiency over a N/A engine but will still need more fuel for the additional load, therefore increasing the amount of fuel being used.
What I'm trying to say the boost will increase the engines efficiency but your MPG will not increase with additional boost. (That made more sense in my head lol!)

 

[TMac]

Making the engine breathe better increases the VE (Volumetric Efficiency), but the more air required equals the more fuel that will be injected to maintain stoichiometric AFR (Air Fuel Ratio). So additional loads like climbing a hill or carrying additional weight will require more fuel and that will not increase fuel mileage. So spooling up the turbo will increase the engines efficiency over a N/A engine but will still need more fuel for the additional load, therefore increasing the amount of fuel being used.
What I'm trying to say the boost will increase the engines efficiency but your MPG will not increase with additional boost. (That made more sense in my head lol!)

I do technical posts (for the most part), and looking at my earlier post, it probably came across as more caustic than it needed to be. So, I'll try to be nicer as I put out information! With that in mind, a turbocharger does NOT increase engine efficiency per se. For the content of this thread we'll define efficiency as BSFC as mentioned before. By its very design a turbocharged engine WILL make far more HP than an N/A engine. That is a given . However efficiency (HP per amount of fuel) is less in a turbo engine.

The reason is due to the following:
1. Thermal efficiency- a modern direct-injected N/A engine can easily have 2 points or more of compression ratio (9.5 vs 11.5)- which is directly proportional to thermal performance. This has a very large effect on BSFC. Mazda's SkyActive engines use compression ratios up to 14:1.
2. Mechanical efficiency- operating a turbine is not "free". It has negative consequences in terms of backpressure, the requirement of additional oil and water pump capacity (minimal but still measurable). Keep in mind that the last 30 degrees of crankshaft action on the exhaust stroke is used to "expel" the burnt gases from the engine. Higher pressures and higher backpressure due to the turbine results in higher "pumping" losses on the exhaust stroke.
3. Inertial considerations- Because it can produce much more HP, a turbocharged engine is generally going to require more robust (heavier) components for pistons, connecting rods, etc. All of which increase rotating mass.

Now these are facts. Turbos are great for making HP, but they do not make an engine more "efficient" than an equally well designed N/A engine.