Getting dissapointing fuel efficiency lately

Yes, aggressive driving hurts mileage that much. You need to change this if you want to see an improvement. I'm getting in the mid 50's out of my '03, with a very highway biased driving environment.

As for your dealer, I would say to find another as well.

 

I don't have a Prius...yet. What constitutes aggressive driving?

 

Speeding, jack rabbit starts, hard braking, weaving in and ot of lanes to work through traffic, blocking other drivers when they need a lange change, tailgating, etc.

 

I'm not sure how I want to respond to this one. Wolfman is correct for the most part, in my opinion, aggressive driving is simply is one step below driving recklessly. However there can be benefits to driving aggressively.

Speeding . . . The Prius gets it best performance at a certin speed. You COULD improve milage by slightly doing over the speed limit.

Jack Rabbit starts . . . I have heard that this could be a good thing. Get the car up to speed, then let the ICE shut off. ??

Hard breaking . . . given the choice between hard breaking and hitting something, I choose hard breaking. I am sure there is more benefit to leting the car "coast" more then what would be recovered in the regenerative breaking.

Blocking other drivers . . . this is just plain stupid to do, it only adds to road rage. I totaly agree with Wolfman here.

Tailgaiting . . . While I don't do this much with my 4Runner, due to the additional stopping distance required, I could see some big benefits of tucking up behind a semi, or other vehicles. The "drafting" ability should add a lot to your fuel efficeny, however the "risk" of not paying attention could be too great.

To sum it up, aggressive driving in some ways could improve performance, however, I always try to use my vehicle to get me from point A to point B, with safety in mind first and formost. The efficiences I would save in gasoline very minor, so I dont plan on trying to squeeze as main MPG's out of the car. I plan on driving my new Prius as I would most any other vehicle. I am sure there will be times I try to run on "Stealth" when there are no others around, but if I am in traffic, I plan on going with the flow of traffic.

 

html,

I agree with you totally. I was just throwing out some examples and some thoughts.

The speeding issue, would be in regards to a 35 or 45 MPH posting. I am sure there is a sweet spot for the most efficient speed. this could be more than the posted speed limit. There are also variances in the roads, hills, etc. which could effect performance. I don't advocate speeding.

:evil2: Just playing devils advocate.

Anticipate stops is always good. I do this now. I've driven a motorcycle for most of my adult life. It has also taught me how to watch for so many other things out there. Animials, kids, other drivers, pot holes, rocks, slick streets, you name it.

I have about another week and 1/2 before my Prius arrives. I'm really excited.

Perhaps my driving style will change. If it does, I will be the first to admit it. It wouldn't be the first time that I changed my point of view, after experiencing something.

 

It would also help if we knew where you were.

Cold weather and winter conditions can have a huge effect on mileage.

How many miles have you logged on your car so far?

Are your average trips short or long? Have they gotten shorter on average since you got the car?

Gasoline in some states changes during the year, the "winter" gas can cause lower mileage.

You can put your location into your profile so it will show up on all your posts --- there's no need to be more specific than your state unless you want to.

With the '04 model, both my husband and I drive. I drive for maximum efficiency, he drives to get us where we're going (safely). I can usually eke out about 2 more miles per gallon ... (me 48 / him 45-46) for the exact same trip (well, same route, ya never know with traffic, but for a 100 mile trip, it's a pretty good experiment). So driving styles can have an effect.

 

Hey Bandit?
If it is getting substantially warmer where you are, then you may be able to put a bit more gas in each time and that may make your calculated mileage look artificially low for a while this time of year. Lots of ifs. Where are you? Has it gotten better?

 

Bandit, if you're seeing a slow, steady decline in MPG, check your tire pressure.

I have been very consistently getting 55 - 57 MPG each tank. I took the car in for the 5,000-mile service, and IMMEDIATELY started getting 51 - 52 MPG. That's a 10% drop, and my wife and I were doing the same driving we were before.

I had completely forgotten that as soon as I got the car home I inflated the tires to 40/38 psi. As part of the service, they rotated the tires and adjusted the pressure to the recommended 35/33 psi. Those 5 psi made all the difference; I restored the tire pressure I had and the mileage came right back to what it was before.

Tires will lose pressure naturally (some say 1 psi per month) so check to see if yours have drifted down - especially since I wouldn't trust your dealer to pay attention!

 

bandit,

has your dealer recently replaced your engine oil? - if they overfill even by a small amount this can have a drastic effect on MPG. If you don't trust your dealer they may very well have done this.

Check the level on the dipstick.

Regards

 

Yeah, "drafting" may add to YOUR fuel efficiency, but it's going to be detrimental to the semi, so what's the point? A lot of people drive a Prius to cut overall dependence on oil; making a less fuel-efficient vehicle pick up the slack is just selfish and completely defeats the purpose of having a PZEV. Why not just hire a tow truck to drag you around town? Then your fuel efficiency will be infinite while still being able to destroy the environment.

 

Paul, I have to question the assumption that drafting is detrimental to the Draftee.

Now, I'm not saying it's safe, but.

From an aerodynamic standpoint, I don't think it's a drag on the draftee, and is usually in fact a help.

Lets take Nascar for example. Two cars drafting go faster with less fuel than one car alone.

The Front Runner is already punching the hole in the air. All you are doing is extending the hole. If you were large enough, you would help the Semi's fuel economy by eliminating the suction/drag from the air backfill behind him. Thats what convoys of semis, and Nascar racers do.

But, you aren't really going to have a large enough aerodynamic footprint to affect his air flow, so you won't be helping him.

But I don't think you'll be hurting him either.

Edit to add Google Findings

http://www.discovery.com/area/skinnyon/ski...2/skinnyon.html

So in front of a truck is a block of high-pressure air; behind the truck is an envelope of low-pressure air. If you can fit your car (or at least the blunt, air-plowing parts of it) into that envelope, you'll have to push less air and your gas mileage will improve. Furthermore, you'll be doing the truck driver a favor: Even within the low-pressure zone, the front of your car is creating a little high-pressure zone, and giving the truck a little push. Race cars lined up nose-to-tail all benefit from this. Each pushes the one in front. Each except the leader enjoys a freshly plowed path through the air. A train of race cars goes faster than a single car can.

 

From what I've read before, drafting doesn't hold any benefits until you hit 74mph, I believe. Could be wrong on this, but I do believe "drafting" at 30mph isn't going to do you much good.

-m.

 

Well, the effect is certainly more dramatic at higher speeds.

Since the increase in air resistance with speed is non-linear, if you knock off 10% of your resistance at any speed, 10% of the resistance at 70+ MPH is far greater than 10% of the resistance at 30MPH in absolute terms.

 

I drive mostly in the city, lots of stop lights/ stop signs, hence a lot of stop and go traffic. My trips are usually 10-15 mins to and from work, so i get 40-44mpg, not impressive compared to other prius drivers.

So i decided to go on a little roadtrip out on the freeway, see how mileage was out there. i drove 40miles and got :clap: 57mpg! unbelievable! i guess my car has been getting the break-in it needs afterall! :mrgreen:

 

Also don't forget that the low pressure hole the nose of your car is in, isn't providing as much cooling to your radiator and engine. You risk overheating your engine, cooking your oil and other heat related problems.

 

If the engine isn't running, it's not gonna cook