Drop in mileage after adding cruise control

[Dstulp]

I added Crusie control on my 2022 XL, and it seems like there has been a drop in MPG. Almost feels as if the truck is not using the hybrid system to speed up anymore but just the engine. Any ideas?

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[Howard]

Not too surprising. It's been said many times a light foot will beat cc for mileage. On my Eco the cruise will accelerate more rapidly from a stop than I often do if I kick it in before getting up to speed and I can see it calling for more acceleration on your hybrid needing the engine to run.

 

[Gray Goose]

Not too surprising. It's been said many times a light foot will beat cc for mileage. On my Eco the cruise will accelerate more rapidly from a stop than I often do if I kick it in before getting up to speed and I can see it calling for more acceleration on your hybrid needing the engine to run.

Agreed. I only use cruise control to hold speed, not to accelerate. Additional situations where cruise produces less MPG:
Using the brake to disengage the cruise. Braking immediately loses the advantage of coasting. Disengage the cruise in advance of braking to get the MPG benefit of coasting.
On very hilly stretches of road, slowing slightly on the uphill and allowing gravity acceleration on the downhill will produce better MPG than the cruise. Cruise will hold speed through the hills and use more fuel.

 

[Waterick]

I added Crusie control on my 2022 XL, and it seems like there has been a drop in MPG. Almost feels as if the truck is not using the hybrid system to speed up anymore but just the engine. Any ideas?

I (and previous replies also seem to) assume you mean while using it and not just because it's now available? On a hybrid, it is pretty widely known that cruise control produces the most accurate speed control, but not the best MPG. Some reasoning; cruise will prevent you from coasting down a hill by either braking or regenerative braking, which is not as efficient as using the extra speed to get you up the next hill. Cruise control may use much more throttle than you would going up that hill to maintain a most accurate speed. Straight and level roads: cruise is OK for max MPG except when using Adaptive Cruise Control which might not be as smooth for a variety of reasons which range from other cars speed differential to their driver's driving style.

Edit: I should have said engine braking instead of just braking above in the third sentence.

 

[MaverickMom]

I added Crusie control on my 2022 XL, and it seems like there has been a drop in MPG. Almost feels as if the truck is not using the hybrid system to speed up anymore but just the engine. Any ideas?

XLT Hybrid. Just finished a 598 mile drive; all freeway in sport mode. The first 150 miles I used the cruise control and mileage was around 47 miles per gallon. I turned off cruise control and mileage went up over 50 miles per gallon. When I finally went to fill up the truck only took 11.6 gallons. Driving lights off, computer plugged factory 400 inverter and in use the whole time.

This was 4th time this truck made this drive. Each time I have tried drifferent mode/combinations. Sport mode without Cruise control has been the best so far. We didn't need to stop once for gas; only a stretch walk at a rest area.

 

[FamousAmos]

Agreed. I only use cruise control to hold speed, not to accelerate. Additional situations where cruise produces less MPG:
Using the brake to disengage the cruise. Braking immediately loses the advantage of coasting. Disengage the cruise in advance of braking to get the MPG benefit of coasting.
On very hilly stretches of road, slowing slightly on the uphill and allowing gravity acceleration on the downhill will produce better MPG than the cruise. Cruise will hold speed through the hills and use more fuel.

Right! And sometimes it's even smoother to accelerate PAST the set speed, then hit RESUME and take your foot off the gas.

 

[RR - All the way]

I have an EB so do not know about the hybrid CC. On hills, my CC does NOT maintain the set speed. It will go down as much as 3 mph going uphill and it will usually go about 3 mph above the set speed going down the hill. Have had it go to 65 downhills when set on 60. I usually accelerate on my own up to about 40 mph and then hit the cruise and go up to cruising speed in five mph increments; this keeps it from accelerating quickly. I am in Eco when I do this, and it takes much more time to get to 60 then if I used my foot. 21K miles and I have always gotten at least 500 miles between fills. Averaging about 30.5 mpg. 70 percent country roads.

 

[HeyBales]

XLT Hybrid. Just finished a 598 mile drive; all freeway in sport mode. The first 150 miles I used the cruise control and mileage was around 47 miles per gallon. I turned off cruise control and mileage went up over 50 miles per gallon. When I finally went to fill up the truck only took 11.6 gallons. Driving lights off, computer plugged factory 400 inverter and in use the whole time.

This was 4th time this truck made this drive. Each time I have tried drifferent mode/combinations. Sport mode without Cruise control has been the best so far. We didn't need to stop once for gas; only a stretch walk at a rest area.

Since Sport mode favors keeping the engine on in order to have fully charged battery (well, 70% SOC), in order to use the motor for HP & torque assist more often - driving on the highway usually already has the engine on anyway.
In either case when the battery is at 70% and engine not needed, engine can be turned off. Not often on the highway speeds or hills.

I'm betting you saw best in this mode because the motor is used more often for assist whenever possible, rather than the engine revving up & using more fuel, so if any hills below a certain speed best engine RPM.

Also the on-board MPG estimate can be decently inaccurate - but still an interesting observation that wouldn't surprise me.
Sort of how Slippery Mode for city driving can yield better than economy if used correctly.

 

[Gray Goose]

XLT Hybrid. Just finished a 598 mile drive; all freeway in sport mode. The first 150 miles I used the cruise control and mileage was around 47 miles per gallon. I turned off cruise control and mileage went up over 50 miles per gallon. When I finally went to fill up the truck only took 11.6 gallons. Driving lights off, computer plugged factory 400 inverter and in use the whole time.

This was 4th time this truck made this drive. Each time I have tried drifferent mode/combinations. Sport mode without Cruise control has been the best so far. We didn't need to stop once for gas; only a stretch walk at a rest area.

Thanks for sharing the testing. Also need to keep track of the wind speed, direction and temperature. Differing weather factors can have more impact on MPG than a mode combination.

 

[MaverickMom]

Since Sport mode favors keeping the engine on in order to have fully charged battery (well, 70% SOC), in order to use the motor for HP & torque assist more often - driving on the highway usually already has the engine on anyway.
In either case when the battery is at 70% and engine not needed, engine can be turned off. Not often on the highway speeds or hills.

I'm betting you saw best in this mode because the motor is used more often for assist whenever possible, rather than the engine revving up & using more fuel, so if any hills below a certain speed best engine RPM.

Also the on-board MPG estimate can be decently inaccurate - but still an interesting observation that wouldn't surprise me.
Sort of how Slippery Mode for city driving can yield better than economy if used correctly.

Thank you. I found economy mode on the hybrid was the worst for city and freeway. We drove from north of detroit to south eastern Kentucky; lots of hills. I calculated mileage based on leaving the detroit area with a full tank and the gallons of gas it took to fill up when we reached our destination. Sport mode did much better than our last trip in normal mode for sure. Sport mode, 598 miles and 11.6 gallons to fill up when we reached our destination.

 

[MaverickMom]

Thanks for sharing the testing. Also need to keep track of the wind speed, direction and temperature. Differing weather factors can have more impact on MPG than a mode combination.

We were just talking about how we went from Detroit area elevation to Kentucky hilly higher elevation. We are interested to see how the trip back will be as we will be descending from higher elevation to lower.

 

[Snowbird]

I followed the original post's about adding cruise control to 2022 XL's. Someone determined there had to be a forscan setting entered for the brake system. They had noticed a drop in MPG's as well and I think it was on Hybrids.

Not sure this is your issue but perhaps worth a check.

Good luck!

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