Cruise control vs MPG

[YarisOwnersDad]

I got about a gazillion hits on "cruise control" when I did a search to see if this subject has been covered in here. If it has, then it won't hurt my feelings if one of the mods wants to delete this thread.

What I would like to know is how much using cruise control costs in terms of gas mileage. I know that a lot would depend on the terrain, since cruise control would attempt to keep the set speed as you go up steep grades, whereas you might allow the car to slow a little if you were using the accelerator pedal.

Does the use of cruise control completely eliminate the use of DFCO, or will the car go into the DFCO mode automatically on downhill grades, even when cruise control is on?

If a guy got let's say 45 MPG on a long trip on fairly level ground while using cruise control, what would you expect that his mileage would have been if he had traveled the same route at the same average speed without the cruise control and without "hyper-mileing?" I guess what I am trying to ask is this: if a guy is not going to hyper-mile, is he just as well off to use cruise control as he would be to avoid cruise control?

Tom

[BailOut]

It is difficult at best to measure exactly how much more fuel cruise control uses, but in the testing that hypermilers have done a 5-10% hit is common. This is mostly due to the lateness and level of acceleration used by the cruise control.

[yaris-me]

You would still have DFCO with cruise control.

[YarisOwnersDad]

You would still have DFCO with cruise control.

You mean it would still go into the DFCO mode with the cruise control turned on? Would it go into it as quickly and stay in it as long?

Tom

[firemachine69]

For as long as the speed doesn't fall below what the cruise is set at.

[Cosworth]

i set the cruise control at a certain speed, and coast or accelerate using the cruise control stem to accommodate the terrain. I don't know how much gas I'm saving by doing this, but as long as I get over 40+ mpg on a long trip, it's so worth it.

[nsmitchell]

I have the Rostra Cruise control with my Yaris LB Auto. I get around 38MPG on the highway doing about 65MPH. I can easily get better than 38 in the city. The Rostra just tries too hard to keep you at the set speed. I wish there was a way to make it more lenient on the gas when going up hills so it doesn't floor the gas and throw off your MPGs.

[nsmitchell]

I do like my cruise control to keep me from getting tickets which can drain your wallet faster than great MPGs can fill it. ;)

[BailOut]

I do like my cruise control to keep me from getting tickets which can drain your wallet faster than great MPGs can fill it. ;)
Paying attention doesn't cost anything at all. :wink:

[nsmitchell]

Paying attention doesn't cost anything at all. :wink:

By using cruise I can keep my eyes on the road and not my speedometer...

[voodoo22]

Paying attention doesn't cost anything at all. :wink:

Wrong, it's inconvenient and I won't waste my time doing that when I could be texting, reading my email, making a call, adjusting my stereo, browsing my ipod play list or making sure I don't spill my coffee. If you are unimportant, have time to plan your day and be responsible, I guess you're just not as important as I am!:tongue:

[2009Toyotoad]

Wrong, it's inconvenient and I won't waste my time doing that when I could be texting, reading my email, making a call, adjusting my stereo, browsing my ipod play list or making sure I don't spill my coffee. If you are unimportant, have time to plan your day and be responsible, I guess you're just not as important as I am!:tongue:

You forgot checking stock quotes, e-purchasing flowers and takeout dinners on the trip home. Your schedule or Techno toys sound a bit weenie to me.:biggrin:

[jambo101]

I believe you get better gas mileage using cruise because your speed isnt fluctuating,as an example with the cruise off and driving on a level interstate i sometimes find my speed creeping up to 80mph and i find that i'm backing off the throttle frequently.

[YarisOwnersDad]

I believe you get better gas mileage using cruise because your speed isnt fluctuating,as an example with the cruise off and driving on a level interstate i sometimes find my speed creeping up to 80mph and i find that i'm backing off the throttle frequently.

Same here. If I don't keep constantly checking my speed and just drive merrily along my way, when I do check my speed, I am often up to 80 MPH, like you say.

I think on level terrain, cruise is a good thing. In hilly country, I think it's best to leave it off, if we want to get better MPG.

Tom

[SpaceShot]

I also got the Rostra unit for my LB and for my route of 40 miles interstate and 15 miles country 2 lane, the trip average Mpg was down 1/2 to 1 Mpg. (compared to carefully watching and maintaining my speed)

Years ago after market cruise systems were vacuum driven and could drift as much as 5 Mph, today's units are computer driven and lock in to +/- 1.5 Mph or better. Thus for my route what gets saved in some lower speeds on certain stretches gets eaten up by less coasting.

It's more of a comfort thing for me and 1 of the 2 mods that really didn't pay back.
(The other was smooth racing disc hubcaps, but I still like the look.)

[twowheels]

Why do people talk like it's all or nothing?

I drive a long straight route using cruise all of the time and use cruise when I want to lock the speed at 55 MPH exactly on the straight/flat sections where I would otherwise tend to let the speed creep up, and cancel it whenever I want to slow down or am on a hill. I never use the resume functionality and instead just get up to the speed that I want and then press "set" again to avoid the fuel blip that you otherwise get. I get high 40s.