MPG hit with cruse control

devin1955 · 01-05-2008, 06:04 PM

Can any of your guys with a cruse control, especially with a 5-speed car, comment on the MPG hit you experience when it's in use? I would well imagine it would be significant, and that's making me shy away from the thought of adding one on my car.

The Insight is the first car I've owned in years that didn't have a cruse control, and I miss it on long drives, but my primary interest in having the Insight is fuel economy.

boogetyboogety · 01-07-2008, 07:08 PM

Can't help you with your MT, but our CVT on Rostra-Cruise mode gets ±5mpg less on highway cruise at 65-75mph than when I pulse-and-glide at the same speed... on loooong trips, well worth the slight hit on mileage for the convenience, IMHO. YMMV, but I wouldn't sweat it if I were you...

Full disclosure:
LMPG: 55.9
43,000+ miles
A/C on Econ/72° and has NEVER been turned off
50# air in all 4 tires

LoNOx 1 · 01-07-2008, 11:35 PM

This summer I tried using cruise on the Prius on a trip running 65. With cruise, upper 30's to low 40's. Without cruise, low to mid 50's.

shifty35 · 01-08-2008, 08:22 AM

65 is nice and rolling the whole way up and down... I drove down from Ohio when I bought the car, then down and up to Destin a month later. Cruise control wouldn't have even worked, the car can't maintain speed up those hills w/o a downshift - not without a ton of assist at least.

jfire · 01-08-2008, 11:28 AM

I may be able to help you out. I just installed the Rostra kit on my '01 a couple of months ago. I drive from Roanoke, VA to Richmond and back at least once a week. The drive is all interstate and can be very hilly. I set the cruise on about 70-72mph. On the Roanoke-Richmond leg I get close to 60 mpg, a little better in hot weather, a little worse in cold weather. Windy days will also help, harm mpg depending on what direction it's blowing. On the trip back from Richmond I ALWAYS get worse mpg. Usually 48-53 mpg. The key is to keep the IMA battery topped off. Afton Mountain exhausts my IMA battery going up the mountain, and mpg suffers. I'm sure that if you drive on a more level road without a lot of hills then you should see 70 mpg++. I have gotten 74mpg on my way to DC once I had cleared the mountains. One reason Honda didn't install cruise is because the car will NOT pull a steeper hill without downshifting. There are 3 hills I have to remember to turn off the cruise or it will click off automatically when you lose 5 mph.

All this being said, however, I am glad I have the cruise and am willing to accept the reduced mileage to save my tingling foot! You will lose a little mpg, but to some of us it's worth it.

Hope this helps!

jfire

Dgate · 01-08-2008, 11:37 AM

If you stop and think about it cruise control system's are stupid....that is they are not intelligent and able to distinguish road conditions beyond heavy throttle up and no throttle down hills which doe's not favor economy.
A good driver seeking economy will attack the hill with reasonable inertia that will allow him to progressivly back off on the throttle while still climbing even though some speed may be lost.
Over the apex he will build up speed on the down side using gravity and a light increasing application of throttle ready for the next hill if there is one.
There is no substitute for a good driver where economy is the concern unless boredom sets in on the flat (Desert) where cruise may be justified.

DGate

devin1955 · 01-10-2008, 04:18 AM

Quote:

Originally Posted by Dgate

If you stop and think about it cruise control system's are stupid....that is they are not intelligent and able to distinguish road conditions beyond heavy throttle up and no throttle down hills which doe's not favor economy.
A good driver seeking economy will attack the hill with reasonable inertia that will allow him to progressivly back off on the throttle while still climbing even though some speed may be lost.
Over the apex he will build up speed on the down side using gravity and a light increasing application of throttle ready for the next hill if there is one.
There is no substitute for a good driver where economy is the concern unless boredom sets in on the flat (Desert) where cruise may be justified.

Exactly! Hence my query. I get 66-70mpg on a typical road trip, and I'm thinking about mileage most of the time. With a MT car and the cruse control just blindly trying to maintain a constant speed, I would guess the mpg hit would be quite noticeable. It's interesting that some of the comments here would suggest otherwise.

My daily commute is pretty short, only 25 miles round trip. But my Insight enables me to do semi-regular longer weekend treks without cringing about the price of gas. It's those trips that's making me consider CC, and the terrain I'd be driving over is not a constant. Last couple trips were from the L.A. area to Las Vegas, and to Phoenix. Certainly long enough to wish for a cruse control.

Guess I'll add CC to the bottom of my wish list and see if it ever rises to the top. I've got a couple other items that need to get done first.

Thanks for all the responses!

Willie Williford · 01-10-2008, 01:41 PM

I just completed a trip of over 5,000 miles and used a cruise control most of the way in my 07 FIT sport.

When my grandaughter was driviing she used the "D" mode. When I drove I used the "S" mode. (I always drive in the "S" mode

Under similar terrain and speed she would average around 35.4 mpg per tank and I could average 41+ per tank.

It's a difference in driving style, knowledge of how the engine works, and my training as an "INSIGHT" pilot.

Willie
LOAD and RPM will kill the MPG.
The trick is to find the happy medium.

Dgate · 01-10-2008, 04:19 PM

Willie Williford. So what are you saying.....the cruise control is more economical??...and if so why (It's a difference in driving style, knowledge of how the engine works, and my training as an "INSIGHT" pilot) doe's this have any relevance?
I'm confused.

DGate

Willie Williford · 01-11-2008, 12:26 AM

DGate;
I was basically showing that even with cruise control, two drivers using the same vehicle can get different mileage, one in S and one in D. In the "S" mode you can control the rpm of the engine better, and there is no downshifting to a lower gear when there is enough load on the engine to cause a downshift and the cruise control does not shut down because of the load as it does in the "D" mode....Of course this only is in reference to my FIT.
This is my first experience with a cruise control so maybe someone with more experience can chime in.

Simply said the S mode is like having a stick shift.

Yes cruise control can be more economical, but not in all circumstances.
And yes it does have a "revelance". The best training to obtain better economy in a conventional vehicle is to drive an Insight. (MY OPINION)

Willie