High speed fuel economy

[CVTCivic]

.24 cd helps a lot, but at those moderate speeds like 80 or 90 mph, the hybrid doesn't help to lower the fuel consumption right?

[CVTCivic]

Originally Posted by serialk11r

the good thing about having an inefficient drivetrain is...higher speeds don't reduce fuel economy much XD

With my short geared, big cam V8, I get 25mpg at 60, 22mpg at 70 and 20mpg at 80. Climbing a hill takes barely more fuel than going on flat land because half the fuel goes towards heating the engine oil.

That's great, my little four cylinder car can't deal with Hill climbing lol.

My small 1.5l turbo is pretty fuel efficient at normal speed, I can get 47 mpg at 80 and 31 mpg at 93 mph. But climbing hills kills any good fuel economy and at 130 mph I'm only getting 6.4 mpg

[Phase]

Originally Posted by CVTCivic

.24 cd helps a lot, but at those moderate speeds like 80 or 90 mph, the hybrid doesn't help to lower the fuel consumption right?

Hybrid kind of helps. The engine runs much longer and it takes longer for it to recharge the hybrid battery. And then it’ll switch to full EV mode for only a few seconds, versus up to a few min in low speed driving. The hybrid battery also helps assist at the higher speeds when going up a hill and keeps the rpm’s from shooting up. If it’s a long steep mountain, after the hybrid battery drains, the engine goes insanely high rpm’s and borderline redlines and keeps revving the engine over and over again. So long story short, hybrid battery acts mostly as an Assist at the higher speeds when it gets under load.

[serialk11r]

Originally Posted by CVTCivic

.24 cd helps a lot, but at those moderate speeds like 80 or 90 mph, the hybrid doesn't help to lower the fuel consumption right?

It would depend on the car. Most cars are running at pretty high load at 80mph since most cars can't break 130mph, and new cars come with pretty tall gearing. Most hybrids have electric water pumps which will reduce a few hundred watts of power demand compared to cars equipped with belt driven pumps that are running pretty fast at 80mph, and they usually have access to a slightly taller gear ratio. Other than that the efficiency should be pretty comparable.

E.g. I would expect a modern Toyota Corolla or Camry to get almost the same mpg as the hybrid counterpart at 90mph.

[Phase]

Originally Posted by serialk11r

It would depend on the car. Most cars are running at pretty high load at 80mph since most cars can't break 130mph, and new cars come with pretty tall gearing. Most hybrids have electric water pumps which will reduce a few hundred watts of power demand compared to cars equipped with belt driven pumps that are running pretty fast at 80mph, and they usually have access to a slightly taller gear ratio. Other than that the efficiency should be pretty comparable.

E.g. I would expect a modern Toyota Corolla or Camry to get almost the same mpg as the hybrid counterpart at 90mph.

i doubt that. normal corolla is rated at 40 highway epa. thats at the 60mph moderate test speed. my gfs corolla hybrid gets about 42 mpg with cruise control at 90mph. no way a normal corolla rated at 40 epa highway is boosting up to 42 at 90...

[serialk11r]

Originally Posted by Phase

i doubt that. normal corolla is rated at 40 highway epa. thats at the 60mph moderate test speed. my gfs corolla hybrid gets about 42 mpg with cruise control at 90mph. no way a normal corolla rated at 40 epa highway is boosting up to 42 at 90...

42?? :O Holy crap that's really good.

EPA rating doesn't translate into cruising though since the test cycle is not cruising. Newer 4 cylinder sedans will do high 30s at 80mph no problem these days even if the "highway" rating is lower. I wouldn't be surprised if a new Corolla could get close to 40mpg at 90mph.

[CVTCivic]

@serialk11r

Here is a fuel consumption video of a 2018 Toyota Corolla 1.8 Hybrid at 80 mph (130 km/h). It gets 5 l/100km (52 mpg US):

https://youtube.com/watch?v=LtE6EVWF_Do

This one is the 2018 Toyota Corolla 2.0 Hybrid, it gets 38.5 mpg US at 80 mph (130 km/h)

https://youtube.com/watch?v=NTd4QcyKJUE

Unfortunately those video and driven distance is way too short to really speak about average fuel consumption. Even still the fuel consumption seems pretty similar to a 2017 Honda 1.5 Turbo non Hybrid engine, which I already posted earlier (47 mpg US at cruise control 80 mph = average 70 mph):

https://youtube.com/watch?v=MODJ2J5_ZE4

[Phase]

My Ioniq is all over the place with mpg at 80 mph. Just depends on winds or ambient temps or elevation or whatever the computer wants to do. Some days it’s extremely efficient and some days it’s a guzzler, even when the two situations are almost identical. No idea how to describe it

Long story short, it seems like some aero mods and lowering the overall drag of the car would put less stress and load on the hybrid system, therefore tricking it into thinking it’s driving slower and then boosting the mpg significantly.

[Hersbird]

The drive I do has mostly an 80 mph speed limits and cops around here won't stop you until you are more than 5 over so I set the cruise at 84 mph and have two one hour, 15 minutes stretches at 84 with a 20 min mountain pass in between with a 65 mph limit I set the cruise at 69. Then there is 10 minutes in town total for a 240 mile trip in 3 hours which is 80 mph average zero stops.

I haven't actually done a trip reset on a long 84mph flat run to see mpg there. I'll try that next Monday. I do know I've put 5500 miles on the car in 3 months mostly driving it weekends on that route. It has made that round trip 11 times now. Saved me $530 in gas in 3 months so far compared to the Lincoln MKZ which was only averaging 22 mpg with its 400 hp and AWD. Both cars are similar size.