best mileage with cruise control or no?

I agree with your last sentence 100%.

My own experience over the past two fill-ups and switching from CC to lightfoot proves that a skilled Prius driver will beat CC by a large margin.

 

I use cruise control when I'm lazy and when traffic warrants. I'm often lazy, but traffic is thick where I live.
I can definitely get better mileage on my own.

 

Some of us (OK, me) can't pull off the 'feathering' effectively enough to gain extra MPGs. I stick with CC when I can, and I'll live with the MPGs I get. 48 today, so I'm not crying...

 

I use CruiseControl whenever practical. I have found that the Prius computers do a noticeable better job on fuel economy than my foot can. My CruiseControl rarely varies ±1 MPH from the set speed and is much more sensitive to hills/valleys and rough/smooth/wet/dry pavement conditions.

 

If I didn't use Cruise, I'm sure I'd get much worse mileage to and from work. Cruise keeps me from accelerating past people and jockying for position. People talk about the Prius helping to control their type A driving personality. Well, the Prius + CC is what does it for me. I put in cruise about 64mph on my way to work. Whereas that's 9mph above the speed limit, it's about 6mph below what almost everyone else drives. Using the 1mph up and down adjustments with the CC, I anticipate and adjust for changing patterns in the traffic. Usually, I only have to drop it out of cruise one or two times during the commute (I am conscientous, and try not to make vehicles slow down when I enter the left hand lane).

So, cruise helps me, but it's not a technical thing.

 

By allowing your speed to fall below the mark going up the hill and rise above the mark on downhills, you can significantly improve mileage compared to cruise control.

 

With CC on you can still lightly press on the gas pedel when going down a hill and you will coast. When the car slows to 1mph less than you have it set to, it takes over. I don't know if this improves mpg, but it should.

 

I've found that even on the flats, I can do better than cc. Taken to the extrreme means coasting in neutral and then replacing the lost speed with gentle acceleration, a practice best suited to empty country roads.

 

i use CC 95% of the time. although in my area where there is no flat areas, moderating speeds to take advantage of gravity is advised. CC has a tendency to "overcompensate" at times for very slight uphill slopes if one doesnt bump the speed down a bit.

but for me, in all but the most extreme of hills, using the incremental adjusting technique works for me. in town, using CC forces me to anticipate traffic and not start to space out on other things. i often wondered if i would wear the button out because it usually requires a lot of driver intervention to use CC effectively in city traffic.

i dont use neutral at all but do a lot of coasting. in nearly all situations, i am on multi-lane streets so i will coast up to a light from 5 blocks back if i know the lights will force a stop and h*** with anyone behind me. and yes i have had SUV's go roaring around me just to have to slam on their brakes to stop behind a line a 20 vehicles sitting at the light. but... its their money...

 

Why is it almost always large trucks and SUVs that do that? Oh yeah, That's most of the vehicles on the road here in Texas.