Cruise Control for Long Road Trip

The best hypermilers always 'do it themselves'. While cruise control does react fast to changing inclines, that isn't optimal for MPG.

But among others, it depends on the particular driver's style and terrain and weather. Some do better with CC, some do better without, others get the same either way. Only you can figure out which camp you fit.

But for a 12 hour trip, the MPG difference is probably not a big deal. Maintaining driver awareness while dealing with fatigue and road hypnosis will be far more important. Stay safe.

 

What Fuzzy1 said.

You will need some entertainment of a 12 hour drive, so why not try driving 10 minutes on cruise control 15 minutes off for a few cycles and see which give your better results. For a valid comparison, keep the same average speed over each 15 minutes. You will have loads of time to compare different techniques.

It takes some skill to beat the cruise control, but it can legitimately be done. But, people who "beat" the cruise control often end up with a lower average speed and that is cheating if the goal is to compare a cruise control to an eco driver.

 

I've found the Prius cruise pretty good, watching my ScanGauge instant mileage numbers, it's using a fairly efficiency-biased algorithm. We're not ardent hypermilers, just trying, and for a long highway drive it's an option to consider, will do pretty good, let you relax.

The down side is it won't "Drive With Load", ie: let your speed fall off on upgrades. Also, on steep downgrades it'll start regen braking to hold your speed down. These are instances where you might want to drop out and take over yourself. But all-in-all...

Staying in the right lane, at or under the limit will help mileage too. And/or following a slower moving truck. Not drafting, just to discourage tailgaters.

 

Don't use it!!! That is why no one ever talks about it because most people here like good gas mileage. You will regret it so much because it essentially turns the engine on the entire time, so you use more fuel and your gas mileage suffers a lot!! If gas mileage doesn't matter and resting your foot does, then go for it. But, it was once and done for me! Never again. Cruise control makes more sense in other hybrids, even my other half's Escape Hybrid still works pretty efficiently with it, but for some reason, it sucks in the Prius. Most of my long distance drives are through hilly terrain, so I guess it wouldn't be bad if you had a flat long distance trip, but those just don't exist where I am.

 

^ I'm pretty sure ours goes into "Stealth Mode" when using Cruise at lower speeds. The cut-off is around 75 kmh for Stealth I think.

 

Well, we don't have highways that you can use cruise control on that are less than 50 mph. Those are typically the ones where you go through cities and have stoplights, speed traps, etc. My long distance drives typically have a minimum speed limit of 65-70 mph (as far as following the speed limit - I like to get to my destination in a reasonable amount of time and going 40 mph isn't going to accomplish that.) No stealth mode option there. The engine runs the entire time using cruise control. I haven't been to Canada, so I am not sure how driving there is. But, it is on my list.

 

Well, in order to get a ticket for going to slow in the U.S., you need to be going under 40 mph, so I don't see that happening. It is VERY obvious when you are going that slow on a highway! I routinely drive at least that distance with most of my trips. The worst one being from Atlanta to Chicago and it is surprisingly not to bad to avoid cruise control. I try to stop when I see gas prices nice and low and that helps things. I hope that your drive ends up being more enjoyable! I don't have satellite radio and the radio stations can be hit or miss, so I just put Pandora on my iPhone and hope for the best. Long distance drives are not for everyone, but they aren't so bad in the Prius.

 

I know that route and I hope to go to Duke for graduate school. Drove it not too long ago. Beautiful, but yes, hilly. I ended up taking I-85 the entire way. I would suggest taking I-59 to I-85 if I were you. The I-40 route is going to take a lot more time and put you through much hillier terrain and a bit out of the way. I took that route going to Hickory, NC and it was brutal. I can't say I love I-85 since most of it is two lanes, but it does end up being the best route. You really don't want to go through Asheville unless you are interested in some sightseeing. Stay away from the I-75 route. There are quite a few cheap fuel options on the way.

 

Last week, I drove from NJ to South Va and back and used CC all the way. Over 55mpg real mileage going down and over 57 real for the ride back.

 

What speed did you have it set on? In other words, were you pissing off the other drivers?

 

2mph over whatever the posted speed limit was. About half of Va had 70mph speed limits, so I would do 72. I checked my real speed with my Garmin. The CC does a pretty good job.

 

Wait a second...you have a plug-in, so it can't compare with those of us without a plug-in. I don't know what good mileage is for the plug-in. But, I just know that I got into the mid-30's using cruise control with my Prius. It was a nightmare.

 

On a long trip, using a PIP's not going to make a big difference. I got around the same mileage when I had a 2011 3.

 

I have taken a number of long trips in my Gen3 prius. I have found: How much efficiency you get with the cruise control very much depends on the terrain. Our area of the country has a lot of rolling hills and mountains, so the cruise control tends to cut into efficiency significantly because it cannot "anticipate" an upcoming hill the way you can manually. In those cases, in manual, I gain speed on the downhill and don't worry if I lose a few MPH on the upside. The cruise control is designed to maintain a constant speed. period. So if it has to rev the engine up to 4000RPM to do it, it will. On the other hand, on dead flat highways, I don't see much difference between the cruise and manual. In any event, on a 12 hour trip, you are going to have to use it for at least some of the time. Otherwise it can be fatiguing.

 

Well, then you are very lucky, but I would imagine the PIP is going to get better mileage simply because it can rely on the battery more than the regular version can. My trip from north of Atlanta going through Tennessee to Northern Virginia was in the mid to high 40's. Better than most people I am sure, but I wasn't happy about it when I typically get close to 60 mpg. I would imagine if I am driving across the Midwest where it is relatively flat, I would be a much happier camper using the cruise control. I have never been north of DC, so I have no idea what the terrain is like there.

 

In California the minimum speed limit is 10mph below the posted speed limit.