Acceleration from Stop
#1
Acceleration from Stop
Hi just got a 2008 HCH - started on first tank at 40mpg and after reading posts here am now doing close to 50mpg. Just have a few questions as its kinda tiring to always think of hypermiling and keeping your foot on the pedal - okay to rush to start at 2.5 at the tach and have 3 bars from a stop the ease up when you get to speed ? is cruise control really that much of a FE killer? and if I want to maintain a crusiing speed of 60 for example - is it okay to accelerate to 70 , then start cruising to a 60 - or should i just feather from 40ish slowly to get to 60?
#2
Re: Acceleration from Stop
Welcome to the forum Chuck;
The topic of acceleration is still being debated (and will stay that way for a while) by the local GreenHybrid community. It just seems everyone has their own idea of what is best. However, the hypermiling community believes any brisk acceleration can only be OK if it is brief AND with a BIG compensating glide or steady state following it. That's is why we always recommend a slow acceleration (below 2000rpm) for better FE. Many of us will not even let the RPM creep above 1500 rpm either.
The other goal is to also avoid the use of electric assist whenever possible while quite a few tricks can be used to make this possible on a regular basis , the main criteria remains that the launching RPMs must be low too.
I suggest that you experiment with the acceleration rates yourself and see what works for you.... then use whatever you can out of Tarabell's article and refine your approach.
Cheers;
MSantos
The topic of acceleration is still being debated (and will stay that way for a while) by the local GreenHybrid community. It just seems everyone has their own idea of what is best. However, the hypermiling community believes any brisk acceleration can only be OK if it is brief AND with a BIG compensating glide or steady state following it. That's is why we always recommend a slow acceleration (below 2000rpm) for better FE. Many of us will not even let the RPM creep above 1500 rpm either.
The other goal is to also avoid the use of electric assist whenever possible while quite a few tricks can be used to make this possible on a regular basis , the main criteria remains that the launching RPMs must be low too.
I suggest that you experiment with the acceleration rates yourself and see what works for you.... then use whatever you can out of Tarabell's article and refine your approach.
Cheers;
MSantos
#3
Re: Acceleration from Stop
Just to let you know what I do when I accelerate from a stop: I accelerate slowly and always readjust my foot so the FCD is at 50 mpg or more. Accelerate a little at a time always watching the FCD. Once I get to 35 mph I try to get the FCD closer to 75 mpg and 100 mpg. My main priority is fuel efficiency so I look at my FCD more than my speedometer.
#4
Re: Acceleration from Stop
Thanks guys. How about cruise control? Is there a big difference with using cc vs foot on pedal - assuming highway is relatively flat?
I have tried both doing the hypermiling tips vs cc and I get not that much difference. 2-3 mpg better on foot on pedal.
I have tried both doing the hypermiling tips vs cc and I get not that much difference. 2-3 mpg better on foot on pedal.
#5
Re: Acceleration from Stop
The biggest difference between CC and manual is that with manual you can slow down a bit going uphill and speed up going downhill and gain momentum for the next hill. If you are on flat land there will be very little difference.
#6
Re: Acceleration from Stop
For level (and I MEAN level) ground, Cruise Control is OK. Most people (if they concentrate) can do better using manual foot control. However, most people don't concentrate, so using Cruise Control can result in better fuel economy for them.
For hilly or mountainous driving, Cruise Control is a weak substitute for manual foot control. I just got back from a 4300-mile trip, some of it through mountains, and I experimented both ways. It's REAL obvious that using Cruise Control up relatively steep inclines is BAD for MPGs. The Cruise Control revs the engine WAY higher than necessary and almost totally disregards using the hybrid battery's ability - even if you were trying to maintain your speed up that incline. It basically accelerates like a bandit using only the gas engine. I saw many times where it hit 5000 rpm and higher. AND added an unnecessary bar of charge to the hybrid battery (a very odd and wasteful behavior). Taking essentially the same incline use manual foot control, I could maintain my speed using only about 3500-4000 rpm.
Colby has it right, if you're shooting for better fuel economy. I do this often, on even small hills.
For hilly or mountainous driving, Cruise Control is a weak substitute for manual foot control. I just got back from a 4300-mile trip, some of it through mountains, and I experimented both ways. It's REAL obvious that using Cruise Control up relatively steep inclines is BAD for MPGs. The Cruise Control revs the engine WAY higher than necessary and almost totally disregards using the hybrid battery's ability - even if you were trying to maintain your speed up that incline. It basically accelerates like a bandit using only the gas engine. I saw many times where it hit 5000 rpm and higher. AND added an unnecessary bar of charge to the hybrid battery (a very odd and wasteful behavior). Taking essentially the same incline use manual foot control, I could maintain my speed using only about 3500-4000 rpm.
Colby has it right, if you're shooting for better fuel economy. I do this often, on even small hills.
#7
Re: Acceleration from Stop
Thanks - yeah cruise control for hills a killer. Also - i get pretty much the same average when i go 1 mile 3000 rpm the cruise /glide for 2 and when i gradually go 2 miles accelerating then 1 mile cruise/glide . So I guess you have to find what best suites you.
#9
Re: Acceleration from Stop
I agree, Chris, but thinks it's worse than your average car on the Civic Hybrid. I think it's partly because the Civic Hybrid's ICE is so small, and the Cruise Control logic/mechanics don't consider or use the hybrid battery's capability at all in order to - run up that hill.
#10
Re: Acceleration from Stop
I agree, Chris, but thinks it's worse than your average car on the Civic Hybrid. I think it's partly because the Civic Hybrid's ICE is so small, and the Cruise Control logic/mechanics don't consider or use the hybrid battery's capability at all in order to - run up that hill.
Remove the mountain hills from the equation so that you're left with the more common flat or slight or moderate hills. In these conditions, cruise control on the Civic Hybrid works as expected and assist and regen will happen whenever it is applicable as if you were controlling the accelerator yourself. Cruise control on the Civic Hybrid is no different than you manually and diligently maintaining your speed. It was never a mind reader. So, if you want to speed up approaching a hill, taper off your speed near the crest, or kill the engine and glide the way down, that is your own creative input into speed control and it has nothing to say about how cruise control works.
Mountain highways are a weakness for any four cylinder car.
Last edited by spinner; 04-12-2008 at 03:58 AM.