Fuel consumption

Lodrun,

:welcome: to PRIUSchat. :cheer2:

Given the scant information that you have provided, there is no way
to tell if there is anything wrong with your car. Chances are it's OK,
and all that is needed is an attitude adjustment on your part to get
the FE/MPGs you've heard about.

There are innumerable threads here on how you can increase your
mileage with litle effort. So, I recommend that you use the search
tool to dig into the gold mine of info at your fingertips.

That said, here are a few ideas to consider:
* Run your tires at 42 psi front, 40 rear
* Short trips -- less than 10 miles or so -- are FE killers
* Carrying extra weight saps FE
* Stop-and-go driving reduces FE, learn to "drive without brakes"
* Overly rapid starts reduce FE
* Trying to run on the HV battery alone uses extra gas (?? Not
intuitive I know, but you reading here will tell you why.)
" Grill blocking" retains engine heat and increases FE.

Well, there's lots more to add. You'll be better off if you read about
all this on your own.

Hang in there, you can do it. Good driving and high FE/MPGs to you.

 

Also, keeping your car outside in winter-time is absolutely lethal to FE.

 

That is equivalent to 28 miles / US gallon, which is quite bad.

I also recommend that you check tire pressure, and inflate to 42/40 psi. Check wheel alignment and make sure the parking brake is not dragging on the rear wheels.

What happens when you take a long road trip of 100 miles or more? What is your fuel consumption then?

 

If my conversion is correct that would be about 41 mpg is US gallons. That's not bad mileage. My 2008 averages 40 to 45 mpg during cold weather and 45 - 50 mpg during warm or hot weather. All my number and most of the other numbers you are seeing are in US gallons.

 

You got your conversion wrong. Imperial gallons are larger than US gallons. It ends up being about 28 miles per US gallon. See [ame=http://www.google.com/search?q=34+miles+per+imperial+gallon+in+miles+per+us+gallon&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a]34 miles per imperial gallon in miles per us gallon - Google Search[/ame].

Since this is your first post, it'd be helpful to copy and paste the questions from http://priuschat.com/forums/gen-iii...ry-copy-paste-fuel-economy-questionnaire.html and answer the best you can. Otherwise, we don't have much to go on.

 

Thanks. Math was never my strong suit.

 

Yikes that's bad! I use mine as a cab and still get around 47 mpg over the winter time. 99% of my work is stuck in town with lots and lots of bumper to bumper crawling at 20 mph. This is where the Prius comes into its own. On a long motorway run I can easily get 60-65mpg.

Check the tyre pressures. I've found the Prius is very susceptible to tyre pressures. If you are low even by a few psi on one tyre it will affect things noticeably.

Some of our US friends run their tyres much higher than the Toyota recommendations as this gives them much better and more reliable economy but beware that doing this will affect your steering and handling - esp in the wet! Also, if plod checks them after an accident you could be in the smelly stuff upto your neck!

So, check tyre pressures, air filter or service records, make sure the oil is the correct type and ease off with that right foot of yours a little.

 

TP indeed has a large factor. My avg has been stuck around 45-47mpg since i bought the car. My best was on a trip to roswell NM where i got 56mpg when i pulled into my hotel. I just DRIVE it anymore. I normally fill up around 430 on the tank, which is pretty good..i can stretch it..but don't risk it.

leave my TP at 40/38 give or take. I used to run like 45/43..but forget it WAY to bumpy. I would rather waste 1-2 mpg..than have my teeth rattle around in my skull.

 

Can you please copy and paste the questions from http://priuschat.com/forums/gen-iii...ry-copy-paste-fuel-economy-questionnaire.html and answer the best you can? You've answered some items already but there are some details that'd help. What are the "legal speed limits" there? I've never been to Europe so I have no clue.

There are a few things you ought to do before getting it "checked". If you were to get it checked, I'd have the alignment checked but do those other things first.

If I read you right, those 47.5 mpg are in Imperial gallons, right? That would be 39.55 miles per US gallon.

 

Hi Lodrun. At motorway speeds the prius fuel efficiency definitely starts to go down, so you should be able to get better FE at lower speeds. Usually I get my best fuel efficiency on quieter rural roads with lower speed limits. Most people can get over 60MPG_UK (50 MPG_US) fairly easily under those conditions.

Tire pressures of 38/36 shouldn't cause any big MPG hit (as compared with 42/40). Cold weather and short trips are the biggest MPG killer, though I know there's not much you can do about that. The type of tire you use is also important. Make sure you choose a low rolling resistance tire when you replace your OEM tires. What tires (size and brand/model) are you currently running?

 

In the US many auto parts store would check the 12 volt battery for free, I do not know about how true that is in the UK. Like any car, the 12 volt battery lasts about 4 years. (yours would be an early failure) Some failure modes in a Prius has the car constantly trying to recharge the 12 volt battery, which is a direct hit of FE, sometimes by 10 MPG.

 

Have you blocked the grill? There are great threads here for both gen2 and gen3. That greatly speeds the warmup which is pretty significant with your shorter drives. Only costs a couple of bucks in pipe insulation.

 

You're in England, and Global Warming is in full effect there - snow and record cold temperatures!

In the winter, your economy WILL SUFFER. While the engine warms up, you will get CRAP for fuel economy. If your commute is short enough that the engine doesn't have enough time to warm up, your trip will be in the CRAP period of fuel economy.

I watch the histogram while driving my car, and the first 5 or 10 minutes are CRAP, then it climbs up. My commute is about 15 miles one way, so the engine gets warmed up about halfway through, and the last half of my commute is in the low 40mpg range, which is normal for winter in the US.

Of course, that averages out lower, due to the first few minutes of CRAP economy.

How far are you driving? How long between trips?

One thing you might research is blocking the front grille. This can help the engine warm up quicker and retain heat longer in the cold weather. Lots of people use pipe insulation, but there is a company that makes a panel that fits over the lower grille.

When the weather warms up, you'll see your economy increase greatly.