Disappointing mileage

There are a lot of factors we see low mileage such as...

• break-in period - We'll need at least 2000 miles to see a normal results, especially with new tires
• short trips - We'll need an extra warming up fuel other than the driving fuel
• A/C use - We'll need an extra fuel for the A/C system energy other than the driving fuel
• hybrid driving skills - We'll see better and better mileage numbers after learning how to drive our Prius
• highway driving - Above 46 mph, the engine is always spinning, therefore we see low mileage. Also, we see stronger air drag at higher speed
• too many stop&go - The best one is non stop 25 - 35 mph driving
• steep hills - A flat or very gentle up/down hills are good
• cold weather - We'll see lower mileage on cold weather than the warm weather
• low tire pressure - We have to set the tire pressure at least recommended value, but higher is better

If you understand these, you have an opportunity to see more than 85 mpg results.
http://priuschat.com/forums/gen-iii...10-mpg-stats-post-them-here-7.html#post874637

Hope this helps,
Ken@Japan

 

Unfortunately, it is people like me posting decent FE numbers that can make you wonder what is wrong. Why would I get better numbers than you?

1. I've driven much farther than you, so the car is breaking in a bit more. My first trips didn't have the kind of mileage I've been getting the past two weeks.
2. I've been driving for decent fuel economy for many years, so I probably have developed patterns that benefit mileage.
3. I've been driving a Prius for several years -- nothing beats that experience.
4. Much of my travel of late has been longer trips that have been conducive to good economy and high MPGs.
5. I'm not reporting just one tankful of gas. (And you really don't know exactly how full the tank was!)

The good news, of course, is that all of these things will equal out as you drive longer in your new Prius.

Whatever you do, though, just try to learn about and enjoy your car for awhile. Don't get too concerned about fuel economy right now, and don't drive just to try and use the battery. That will work counter to your interest in being more fuel efficient. You would do better just driving it like any other car.

Speaking of just any other car: Do you recall the mileage you had on your first tank in the Smart car?

 

Next time try blending 87 and 89 octane to meet the recommended 88 octane per the manual. My suspicion is that 50 MPG combined was achieved using 88 octane fuel. I don't buy that it was a typo on the manual. Of course Toyota will say that you can use 87 (as with any car that requires 91 premium) but you may not get the same performance. Currently on my 300 mile Prius I have averaged 48 MPG. It has about 1/2" tank so it is time to fill up with some decent gas. Also check the tires pressure, my front tires came under inflated from the dealer.

 

I Avg.800 miles a week, Sometimes 200 a day on my '06 until last week I never avg. below 47 mpg usually right at 50 mpg. In Jacksonville,Fl its 95-97 Degrees my mpg has dropped has been 41-43. I do blast the AC . But I dont remember last summer my MPG being that poor .I still employ the Pulse and Glide method but it hasn't helped much. COLD WEATHER is always better than hot for MPG>

 

I live in a very hilly area and I am getting 52 mpg on first tank. I am not doing short trips and I keep it mostly in eco mode.

 

FYI,
It was confirmed that the 88 octane value on the manual was wrong.
http://priuschat.com/forums/gen-iii...-octane-2010-prius-whats-up-5.html#post858305

Ken@Japan

 

I guess 'cold' is relative. For those of us up north, cold weather -- icy, snowy winter -- is always worse for MPG. Best MPG occurs in the warmest weather one can tolerate without AC, which here happens in the summer.

 

well the OP states he got 43 mpg, the display says 47 mpg, that is close enough for the first fill. dealer just did not have it as full as the OP.

but as far as your mileage goes. you have one big hitter after another. short commute, heavy stop and go traffic with AC. its all gonna drop the mileage.

first thing, try to anticipate lights. are you on double lane roads?, if so, try starting your coast a few blocks before the intersection. in most cases, you waste less gas, regen more, and spend less time at a standstill waiting for the traffic to start moving again.

on your AC, i lived in your area, and even if the temps were in the low 80's, the humidity makes AC a requirement and not an option so not a lot you can do there. but one thing i will say, turn off the AC and run straight fan for last minute of your drive. this will help prevent possible mildew forming on the core. you might be in a warm enough area where it will not be as much of an issue, but i would do it anyway.

pump your tires. for in town driving, i would not run anything under 42 PSI. this can bump your mileage up 1-3 mpg and increase your tread life. now its supposed to make it a rougher ride but i have never really felt much of a difference.

 

My first tank was dealer 'filled,' 89 octane, Shell E10, and even so, I was pleasantly surprised by the calculated milage. I ran the tank dry (or rather the first error message), put in 1 gallon spare and then drove to fill with straight gas. The current tank is just under mid-tank level and the trip meter is looking better.

Bob Wilson

 

,
Good point. I guess there is always that huge expectation of 50+ fuel efficiency in your first tank, especially for first Prius owners (like me), so it can be really frustrating to see that not happening. I believe I have good driving habits because I get an average of 26-27MPG in my AWD CR-V (mixed city/hwy) in the summer, considering that EPA estimates for it are 20/26. So I'm expecting to get around the upper end of EPA estimates for my new Prius just using the same habits, but I guess I should lower my expectations just a little bit, at least for the first couple of hundred miles due to the several factors already discussed here.

 

It may be a good idea to keep you expectations on hold for the first couple of tanks, but if you are going to be driving those large highway miles in IN, IL & WI at this time of year, then you should be seeing the EPA FE numbers fairly quickly -- unless you have a leadfoot, accelerate very hard, have to be "first" in whatever line exist, run A/C at high, etc.

 

I got my Gen III 2 weeks ago, with 30 miles on it. When I got it, average mpg was only about 33. The first tank ful averaged in the first thirty miles, and the mileage was lower than expected. It has been going up since, and mpg is now around 50--mostly around town. Whatever they did with it at the dealer, the first thirty miles it got terrible mpg. I'm guessing it sat and "idled" a lot?

Listen to me--33 mpg is "terrible" ???!!!???

 

I see...

My new commute (going from Indy through the wind city until Madison round trip every week!) is not starting until mid-September... so I will have time the break-in before that.

 

The first 30 miles probably consisted of short test drives, moving the car around the lot, etc. It never had a chance to warm up. This is killer for mpgs. You getting 50 now, while still on that first tank, means the car is capable of getting much higher than 50 mpg on your next tank.

 

Seriously, I hope to keep all this in perspective. I'm getting a Prius so I don't have to drive a Ford Expedition (14.5mpg) around as a daily driver. The thoughts of 50 mpg really intrigue me and it was a factor in leaning that way instead of the Fusion. I had a TCH where I beat EPA by 10% so I really am interested is seeing if I can do that on a Prius. However I'm just curious if I can and it really doesn't matter if I don't. I am buying a V with the 17" wheels so I am already willing to take a hit on FE for looks and handling. If this thing gets anywhere north of 45 mpg I will be ecstatic.

 

Zaxcom, to be explicit, your fuel economy is almost certainly the 47 MPG on the display, not the 43 MPG you calculated manually. There's no way to know how full the tank was when you got it, and so the amount of fuel you put in at the first fill is almost certainly not the same as the amount of fuel you burned while driving. This means that MPGs calculated with that number is almost certanly inaccurate.

 

There was that one stretch of I-94, from about Tomah to Hudson, where my mileage dipped perilously close to 50. I suppose driving 75 on cruise control into VERY strong headwinds (on a cool day) may have contributed to the poor performance.

You better leave sugar and caffeine out of your diet for awhile.

 

Break-in Schedule:
1. Weekend in Brown County (no Interstate)
2. Weekend in the Michigan dunes (exciting drive up through Monon and Michigan City)
3. Ready.

I think you'll like the mileage -- if you can just keep your finger off of that Power Mode button!

 

Great suggestions! I have to include a water park in that schedule too otherwise I will be the one broken-in by my family...