Hybrids and Aggressive Driving

Well.... yeah. That applies to any vehicle.

The gist of the story basically says that under these driving conditions, the advantages of hybrids are lessened. This is true and logical since under these conditions, the hybrid componentry is only minimally utilized.

At high speeds it's mainly the ICE fighting wind resistance - same as a conventional vehicle. In aggressive driving, you may get a boost from the electric motor in initial acceleration, but once you use up that juice (which would happen very quickly), you're not recapturing it during aggressive braking - which uses mainly friction rather than regenerative braking.

good thing i got that accordhybrid

I don't think Toyota was thinking of EPA
developing THSD;
My commuting in my last car (1994 VW Golf Station
1.8 ltr gasoline)
was 28 MPG and at the highway 37 MPG(good!)

In 2006 my Prius figures are:
49 MPG commuting
46 MPG highway

Toyota is just showing how the old gearbox
should be replaced ASAP by more intelligent
designes.

In addition to the regenerative deceleration systems, it is the CVT which optimizes engine efficiency on both the Prius and the Civic. The authors should have addressed that.

At speeds over 40 mph for all the cars, it is simple physics - hp required to overcome resistance. On my ‘03 Prius and my buddy’s ‘05 Prius, highway driving yields 110 mpg minus speed. 50 mpg at 60 mph, 55 at 55, etc. A 5 knot headwind or tailwind is readily seen on the mpg scale. It is essentially the same as increasing or decreasing your speed by that amount. Dave R.

I drive my Prius very fast on my over the mountain commute. I get 32 mpg doing this. All my other cars got 12 - 20 mpg doing this same commute. As soon as I take a trip on normal hiways and get off this commute loop the MPG goes up into the 40s MPG. When I'm driving hot I still brake for corners and go downhill after climbing uphill so the regen is in effect and the battery charge is going from empty to full constantly. When the battery is full I have noticeably more acceleration. I have Michelin tires -- that helps.

Any car will see fuel consumption increase with aggressive driving.

I remember reading an article about a study that was done in Europe. Driving aggressively in town resulted in something ridiculous like 90 seconds in time savings over a 60 km city trip but with 30% greater fuel consumption. I don't remember the exact numbers but basically the conclusion was that aggressive driving saved little time but consumed way more fuel.

I've done the test on my daily 104 km commute. Yesterday I was late leaving for work. I drove like a madman at 140 km/h on the 50 km of autoroute where traffic is sufficiently light to allow that sort of speed. My trip computer registered 6.7 L/100 km. Today I drove at a more gentle 110 km/h (10 over the limit) and the trip computer showed 5.5 L/100 km for exactly the same trip. What really stands out was the time though. On both drives the heavy traffic started at approximately the same point. At 110 km/h, I the drive in to work took 1 hour and 16 minutes. At 140 km/h, the drive took 1 hour and 12 minutes.

Pretty conclusive! Incidentally the car involved is a Passat TDI diesel that averages around 38-40 mpg in summer. When I use our Jetta TDI (I alternate in the summer, but not in winter as the Passat has stability control), I average 47-48 mpg.

I usually drive at 100 (speed limit) and not 110 but I've been experimenting and 110 seems to work better with the flow of traffic with very little penalty in fuel consumption. But I do notice that above 110 km/h, fuel consumption starts to increase rapidly.

I find I get much better gas mileage on the highway instead of city. Even if I drive conservatively in the city. Also, I try to use my cruise as much as possible on the hywy and city and this improves my milage. I drive 100 miles a day on average. I drive approx 65 miles per hour on the hywy and speed limit in the city and I get on average 47 to 52 mpg. I am very satisfied with my Prius.

You're right, Don. At 75-80 MPH my wife's 2004 HCH only gets 43.9 MPG...see my blog trip report at http://www.hybridcars.com/blogs/hybrid-commuter/3611-miles-in-two-weeks.

After reading, that article, I've come to the conclusion that...

Jaguars suck.

Unless you drive like a maniac with them, and unless you're on the highway, you'll get a ticket.

I just came off a 3,099 mile trip driving a Toyota Camry Hybrid. (The car had 1008 miles on the odometer at the start of the trip. Three tanks of gas for those first 1008 miles. Average mileage was 32-33mpg with very short trips 5-10 miles each start.)

The trip started in Livermore CA. and went to Denver Colorado and back. Interstates; I-5, I-80 over the sierras, US-50 across nevada to I-15 Utah and US-50 and I-70 Utah and Colorado. Elevations ranged from lows of 4,500 ft to 6,500Ft across Nevada up across the Continental Divide on US-50 and back through via Denver across the CD again.
At the end of I-70 in Utah we retraced the US50 back through Nevada and into Reno NV and back into California. Temperatures ranged from 95-103 except for the high elevations.

Speed limits in CA 65mph, Nevada 70mph and 75mph in Colorado.

It appears that there is a "sweet spot" between 72 and 75 mph that yields best Miles per gallon. Six tanks ranged from 36.2 to 42.1 with average for the 3099 miles at 39.53mpg. The lower mileages were noted when above 75mph to around 78.

Altitude and air pressure probably affected the result as well as Cruise Control, in a positive aspect.

So far I have not seen the "city" mileage even come close to the stated EPA numbers, perhaps this is due to the extreme short distances of 5-10 miles and not enough time to warm up the engine to get optimal efficiency.

I don't know if 70-80 mph is aggressive driving with this Hybrid but compared to the Prius it appears that the Camry profile is quite different. It will never reach the Prius mileage but looks a lot closer to the Jaguar profile on the high end.

What becomes very apparent is that with CVT compared to 3 speed automatics there is a technique involved and learning curve. I'm not sure that without Cruise the mileage would have been as good as it was. Since you cannot hear the engine when its running on both electrical and gas at effectively 60mpg relative and at 72mph, the human technique is difficult to maintain with consistent throttle.

Take the human out of this equation and put some more electronic controls in its place and 50MPG with this 3600 LB + Camry Hybrid will be achievable in the future.

Driving conditions tell the whole story, hills flatland, stop and go etc. Perhaps Electronic Control will yield the same MPG at the low end and the high end in the future, both increasing mileage. There are so many variables that effect mileage that the high tech cars will have to take control because high tech drivers are not consistent enough to improve mileage from this point.