New owner? Want MPG help? Read this first.

I think I may have a similar situation as you in that I do a lot of short trips in the city, and I've been told the cold weather makes the mpg worse. I am now getting 20-25 mpg since the last few months and have been told by the Toyota dealership that this is normal for people who live in the city in cold places. Not sure what to make of it.

 

Cold weather + short trips is indeed one of the worst-case scenarios for the Prius. That's an MPG killer for any car. But the effect is greater in the Prius because in conditions like yours the engine will never reach full operating temperature and, unlike a fully warmed engine, will never shut down when the vehicle is moving.

I strongly suggest you check out an engine block heater. That should at least get you into 30+ MPG territory. Do a good search for details; there are several good threads on the topic. PC member/Boston area resident Hobbit might be willing to assist with installation if you're mechanically challenged (like me).

 

If i only drove the 5 or six miles at a time im sure milage sufers. I drive some leisure trips farther, and get better mpg. Forget the dataon screen, very inaccurate I use actual gal. and odometer reading at each fill up and avg, 41+ mph still better than even sub compact in other cars. Prius is bigger and more comfortable than small hondas or carollas Don

 

I'd concur with the sentiment that short trips and cold weather KILL fuel economy. I'm a newb here and have had my Prius for about 48 hours... but I had an Insight a few years ago, so I'm familiar with what can affect fuel economy.

Short trips are killer, because the engine won't get to temperature, where it is the most efficient, and in our cars, will shut off when it is not needed.

Batteries also do not perform well in cold weather and need time to warm up.

I found that in the Insight, the optimal minimum drive distance was ~12 miles. That gave it enough time to warm up and regenerate enough so that the battery could assist. I have not yet become familiar enough with the Prius to tell anyone what the optimal minimum drive cycle is, but I'd wager a 6 mile drive is not enough.


Now I live ~23 miles from the office, mostly highway, so I'm hoping the Prius will do well on my commute.

 

this is great link..

 

I have been getting bad MPG since the 40,000 maintenance check and concommital tire replacement (Pirelli P4 88T tires if that makes a difference). It dropped from 53 MPG to about 46 MPG, Toyota dealership is saying I should have gotten their Michellin tires, and gone with their tire pressure recommendations. The tire store said type of tire doesn't matter, just as long as it is the same size. Toyota manufacturer recommendations (found on the door jam) recommend 35-33 tire pressure; Tucson, Az. dealership recommends 38-38, and the chat line recommendations for tire pressure are even higher.
Any recommendations?
Thanks- J. Jones

 

38 all around is the start of getting better results, if the roads are smooth in your area I would try 44fr 42rear. Personally though I run about 50front 48rear on Goodyear TripleTreds in the slightly wider size and I have been hovering around 58 - 62 MPG. Expect about a 5 MPG loss though if you are needing to run the A/C as I expect you most likely do in AZ.

 

Is it advisable to top-off your tank to achieve maximum MPG? I tried to do so the first time and some gas ended-up spilling out of the tank because of air bubbles.

 

From a emissions stand point, it is always bad (on any car) to 'top up' the tank beyond where the nozzle shuts down automatically. On a Gen II Prius it can 'throw codes' requiring dealer service. You can't possibly save time or money compared to not having to visit the dealer by not topping up.

I can think of no possible gas savings topping up, but spilling it is just bad for everyone.

(Was that strong enough without being harsh?)

 

I am a new 2007 Prius owner and I've been averaging around 36 MPG. I drive 20% city/suburb and 80% mostly flat highway going at a sustained 65-75 miles per hour for about an hour. What is wrong and why am I getting such bad mileage? (also, it has been around 30 degrees where I live).

I read the article Galaxee posted by Evan Fusco and will have some patience in terms of the MPG and I will get to learn my car and maximize my driving habits.

However, what I think may be a real problem is my battery...I noticed on my Consumption screen that my battery has never been completely full and green - at best I have only gotten 7 horizontal bars. Shouldn't there be 8 on a fully charged battery?

Any suggestions? With only 50,000 miles on the car could the battery be going already? Please help! Thanks!

 

If you have been driving down mountain passes, that battery should get to 8 bars. Short of that, I see 7 bars when slowing from 61 to 48 as I reach towns. (Should be 55 to 45, but I speed)

In general, you always want some battery capacity 'left over' to handle slowing down, but coming down mountains tends to use all the reserve. That is when you should use B mode, as it is designed to help waste energy, when needed.

I normally average about 43 MPG, but below freezing, I seem to be getting 37.

65 to 75 is not a great range for the Gen II hybrid, I find 61 MPH to be wildly better mileage. At 61 I am getting 55 MPG, at 69 I do 48 MPG, it drops fast past 61 MPH for me.

bwilson4web has graphed his mileage in several vehicles. (we own a NHW20 in his parlance) As you see, he finds a sharp drop off past 65 MPH in his experiments.

 

Nope, that's completely normal behavior. The car goes to great lengths to avoid overcharging the battery, and it generally leaves a little headroom for any upcoming regeneration opportunities. Generally the only time you'll see it "full" with eight green bars (which actually is only 80%) is after a prolonged descent.

As for your fuel economy, first suggestion is to slow down if possible. From there, you've appropriately acknowledged the need to learn the car and to practice. And study the many fuel economy threads on PriusChat. It takes patience and time. Good luck!

 

Much of the gas saved by a Prius is because the Internal Combustion Engine is off more frequently than in 'normal' cars, when it is cold, even a Prius runs the ICE more. (heating the cabin, pollution controls, longer warm up times, more idling by owners, etc.) Without the 'tricks' (stopping the ICE, electric motors, regenerative braking, Atkinson Cycle Engine, etc.) the Prius would have MPGs very similar to the Yaris, above.

The Prius also has a 12v lead acid battery to power up the computers when you start the car and run the radio, etc. when the car is off. In general, a 4 year life is about average for modern automotive lead acid batteries, you may wish to get your checked. If it has failed in just the right way, your Prius can spend a lot of it's energy trying to recharge it, lowering MPG.

 

Dueling Jimbos, it is like Deliverance.

 

All good points and advice...thanks the the help and patience with a newbie Jimbo's!

 

Your article is very interesting and helpful. This week I took delivery of a 2006 with 22,000 miles. The car is a Toyota Certified pre owned car. It looks like new. So far I have driven 350 miles and am only averaging 38mpg. I live in Florida so the roads are smooth and flat. The climate is not to cold and I drive a 125 mile commute 2 times a week. I drove yesterday with the AC off, only the vent on. Still 38 mpg. Today I checked the tire pressures. They were all at 36. I have adjusted them to 40 front/38 rear. Tonight I will see if it makes a difference.

A neighbor of mine drove his to NY and averaged 45mpg. He drives 75-80 mph. I wish I was getting 45. I set my cruise control at 79mph. and I’m at 38. The oil is at the correct level and was just changed. The tires are new Coopers.

I don’t drive the car aggressively or baby it. I just drive it like a normal car. Is my MPG below what it should be? I was expecting more. Are my expectations to high? Any suggestions would help.

Again thank you for your help.

 

My 2006 was getting about 39mpg until I did a tuneup on the ICE: Put new platinum spark plugs, changed the oil, new oil filter, new air filter, pumped the tires up to 47/45, changed the cabin air filter. I live in CA where the temps are moderate. Now we get ~50mpg average combined.

You could also check the compression of the ICE, slow down a bit, make sure your oil is 5W-30 or so, check alignment, turn AC off, and turn the radio off while driving and listen for any unusual noises with the engine or road noises. Could be a sign something's off or broken.

 

Try driving slower and see how your results compare to EPA. I will never know what mine gets with cruise at 79. The slower test will help assess whether your car needs tuning, alignment, etc. Then work your way back up in speed and decide what speed/mileage trade-off you want.

 

I have a 2007 prius, I drive to work 55 miles one way.
I have new tires, yokohamas Avis touring, great tires but the milage went down the first 2,000 miles. I was getting 44.5 -46. Now last fill up I got 48.4. Tire pressure 35, discount tires wouldn't fill it up to 40psi, the tires can handle 50psi max. Two questions, 1. Is this normal? and 2. how acurate is the milage computer??
I drive at 63 MPH up and back and have cruise on. Can I improve it? (MPG)
Thanks,
Pat Alvarez