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Are people really getting 40+ MPG in Gen 2?

Discussion in 'Gen 2 Prius Fuel Economy' started by timmyjane, Apr 12, 2017.

  1. Totemanimalprius

    Totemanimalprius New Member

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    I have 05 prius base. I get 46 to 48 and as low as 33 at super cold temps. I use the cheapest oil and filters. My prius has 245k miles. The lights of death are going off all the time. But i thinknits just a mis read on tbe battery. The car does seen to die. I say "why wont you die!". I would guess somethings off on your car. Hard to say what it could be whithout seeing what you do. Some people arent easy on the car and they do get less from that i have friends that get less because they drive like 900 mph
     
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  2. Data Daedalus

    Data Daedalus Senior Member

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    New tank of fuel a few days ago. This was the result of my commute as of last week Friday. I believe the Esso Petrol Station seems to have had a delivery of ethanol free fuel, though the present heatwave over the UK might also be accounting for this unusually high mpg too!

    Alas, it took a monster traffic jam (on the way home) and short weekend trips, to ruin these figures. It now stands at 64.3 mpg, but dipped as low as 62 mpg over the weekend

    p.s. All UK mpg figures of course


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  3. VFerdman

    VFerdman Senior Member

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    These are Imperial gallons, correct? Not US kind. It would be around 51 US MPG, which is still very good, but not as unbelievable as 62 (US) MPG. I just wanted to clear this up in case US folks start questioning their driving habits.
     
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  4. Data Daedalus

    Data Daedalus Senior Member

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    Yes, imperial gallons which means 65.9 mpg (UK) = 54.87 mpg (US), or 64.3 mpg (UK) = 53.54 mpg (US)


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  5. Coedy

    Coedy Junior Member

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    Just to thank you for your tips on the last page.

    I started doing your main tip which was use the cruise control more and wow! My trips are definitely noticeably better when I do use the CC compared to without.

    My old VW was awful on the cruise control, either full off or full on so I could always beat it, The prius beats me hands down, it manages to glide a lot easier at Motorway speeds than I can.
    I now engage CC as much as I can (If I know there are no tricky junctions coming up) from 40mph upwards as I still don't like using it around town (people see a prius and just tend to pull out in front of you around here).

    Thanks again!
     
  6. #1 Toyota salesman

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    Currently looking at 47 .0 on the MFD , 300 miles in on a highway road trip to Florida, CC set at 69.
    Started throwing MAF code yesterday. Replacing it, some refreshed injectors, and newer coils, next week. I should see even better fuel economy, then.

    Posted via the PriusChat mobile app.
     
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  7. jerrymildred

    jerrymildred Senior Member

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    (y) Cruise control is a big help for me on level roads. Once in the hills, I take over in order to keep the RPMs down and drive more or less like a trucker, slow as is safe going up and making up for it going down.
     
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  8. #1 Toyota salesman

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    Years of driving tractor trailer have trained my foot to drive a Prius as intended

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  9. Coedy

    Coedy Junior Member

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    So do you accelerate into the bottom of a hill and then just maintain the speed best you can without over-revving? Or do you come off CC and then just chug your way up the hill at whatever speed the Prius wants to sit at (within reason)?
     
  10. Data Daedalus

    Data Daedalus Senior Member

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    It is true that it’s generally more economical to climb a hill manually controlling the throttle with your foot, than letting CC drag you to the top. I usually let CC get on with it when I’m going up a relatively shallow incline / gradient at 50 mph for example. If it was much steeper / shorter journey to the top, then I’d do it manually. I’d hold the throttle pedal in place at the speed I want and get to the top. It does depend if it’s a straight road up, whether it’s a winding road, and whether I’m holding anybody up. The steeper it is, the slower I go. I’ll usually use the downward gradient to build up momentum, unless I am prevented from doing so - busy road, cars or trucks ahead, not safe, average speed cams, Smokey at the bottom of the hill .

    On lengthy shallow climbs and drops, CC all the way, especially on a multi lane highway. I especially like how the CC slows you as you dive down the other side. It’s akin to an aircraft coming in to land with air brakes deployed, and below 42mph on my Prius, the engine cuts out and regenerative braking dumps otherwise wasted energy (in any ordinary vehicle) straight back into the traction battery!


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  11. jerrymildred

    jerrymildred Senior Member

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    On rolling hills, I don't even turn on the CC. It took a while, but I hunted for the best combination of safe speed and indicated miles per gallon. It's easier if you can follow a semi at a safe distance and try to keep as nearly constant of a throttle position as you can. It's too bad a cruise control can't be trained to do that. (Well, I think I read somewhere that some really expensive cars can do something like that.)
     
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  12. Data Daedalus

    Data Daedalus Senior Member

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    I do that for rolling hills too. Use the momentum off one hill to climb the next one . It’s almost an art, but it can be done under the right circumstances IF you haven’t got other irate cars snapping at your heels just because you’re automatically perceived to be “slow”.....just because you’re a Prius

    And yes, you are referring to Adaptive Cruise Control - I believe the latest Prius has that functionality available depending on what model spec it is.


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  13. Data Daedalus

    Data Daedalus Senior Member

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    The hot weather in London hit 36c yesterday afternoon. Used my AC in anger (16c, speed 2 on recirculate), and for the first time ever in 5 years, heard my condenser fan (up front) howling like a General Electric Turbofan at idle. It was THAT hot! Traffic was horrendous on my homeward commute, but still arrived with 64.7mpg UK (down from 65mpg UK in the morning)

    Got to work this morning with 3 bars down on my fuel tank and 65.4mpg (UK) on the MFD.

    It’ll be down by the time I get home - I’ve heard there are delays on the route home. Again.

    Have a nice weekend everyone!


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  14. SoTxPlayn

    SoTxPlayn New Member

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    Hello Prius Chat peep...NEWBIE to the Prius world and to here:cool:...As a person from the body shop world, two years ago I purchased a wrecked 2008 Gen2 with 85,000 miles. Gladis sat for two years after the body work was repaired and the brake booster installed. Just recently I put a new OEM 12V Toyota battery in her and decided to drive her. When I fired her up she had 12 year old rotten tires (by date) and 3/4 of a tank with 2.5 year old fuel that ran horribly. I took her to local gas station added 3 gallons of 93 octane and a bottle of rubbing alcohol and proceeded to "burn" the bad fuel out (I'm sure ya'll understand how hard it is to burn 3/4 of a tank of gas in a PRIUS!!:LOL: in my Vette NOOOO PROBLEM :D) Once she got down to two bars, I filled her up with 93 octane and proceeded to drive and that tank got me about 37.9 mpg, MUCH better than my F250 4x4 diesel at a whopping 13.8 mpg but no 40+. I then replaced all four tires with BFG Advantage TA with apx 44psi which felt like basketballs so I lowered them to 35psi, alignment, and a fresh oil change. I am around 1,000 miles since she's been reincarnated and so far by my math I'm getting 34-35 mpgs. I COMPLETELY understand about driving habits have a lot to do with mpgs and I am hoping maybe there are some other H-town Prius owners here that can shed some light.

    Here are my challenges...1) I drive 36 miles to work (72 miles round trip) through down town Houston (NO flat freeways whatsoever) only about 15-20 minutes each way are stop-start traffic the rest is 65-85 mph to avoid being run over by a big F250 (like mine :ROFLMAO:). At lunch I go about 8 miles round trip in traffic to go eat.

    2) A/C--I've read the comments about not using this feature for most but this is Houston. If you have never experienced a summer day in H-town just imagine this being a tad bit cooler than HELL. Sooooo the idea of not using a/c is not even a thought in my mind I will sacrifice those mpgs.

    3) Weight--I don't carry any unnecessary weight in the car but myself (I am 6'1" 290 pound guy) :ROFLMAO:

    After doing much reading on here I am going to try to do a tune up, clean MAF and throttle body, replace air filter, charcoal filter, cabin filter, pcv, and double check tire pressure. Beyond that I am kind of at a loss other than to continue to improve my driving habits. I'm not the guy expecting 50+ mpg but 40+ would be nice to average tank to tank. Hell when my Z06 was stock I got 25 mpgs when I wasn't "spirited driving". All in all I am really liking Gladis for commuting back and forth to work and in the city parking her is AWESOME!!
     
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  15. VFerdman

    VFerdman Senior Member

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    Welcome! Just drive normally and the duel economy will shake itself out. I a thinking your traction battery is probably not that good. 85K miles is low and then it sat for a long time. That is a kiss of death for those traction batteries. If you don't have battery related codes yet, you may want to consider Prolong system to condition that battery back up. Or just drive it until the battery kicks the bucket and replace with a new one. Then you will see 40+ mpg, most likely. But A/C does take a toll on the economy. I am in New England and we had some very hot days. I usually like to drive with windows open, but at times it's A/C or bust. Also, on the highway I will use A/C. In any case, I notice a 5% - 10% drop in economy depending on how hard the A/C has to work. In Huston, I imagine it works pretty hard.

    Enjoy the car!
     
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  16. Data Daedalus

    Data Daedalus Senior Member

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    Welcome, SoTxPlayin! I’m presuming you are resetting your Energy consumption meter on the MFD (Multi-Function Display) each time you fill her up with fresh fuel?

    This is important in order to get a more accurate reading.
    Those new tyres; are they “Low Rolling Resistance” Tyres? LRR Tyres are really what are needed on a Prius, to aid it in getting excellent MPG economy figures.

    I’d set your tyres as follows;
    Front: 39 psi at least.
    Rear: 37 psi

    You will notice a distinct difference on how she rolls after you do that. I’ve got mine at F40/R38, and that’s rather excellent for hypermiling - which is something you’ll soon pickup.

    While you can drive a Prius pretty much like any other car, to get the best MPG figures out of it, and take advantage of the advanced Hybrid Synergy Drive Propulsion Unit, it’s probably a great idea to read up (or watch YouTube videos) on Prius specific hypermiling techniques.
    Some are easy to pick up, others you hone to perfection with time.

    A/C: The Prius was designed to be used with its climate control systems in hot weather, and you simply do not incur the same penalty for using it, as you would with a standard “Internal Combustion Engine” powered vehicle. The A/C in a Prius runs entirely off the HV Traction battery at all times.

    In hot weather, I’d recommend ALWAYS running the A/C. Why? The cool dehumidifies air pumped into the cabin is then sucked into the HV Battery Matrix, and blown over the battery cells to cool them down.

    There’s a school of thought that suggests this doesn’t make much of a difference cooling the battery cells - but from personal experience, I totally disagree with this. Note that the high MPG figures I get every summer, are accomplished with A/C use during my commute every day! Morning and evening at the moment, due to the heat wave in London.

    The secret to better MPG while running your A/C is to never use it in Automatic mode. It seems that uses more energy from the HV Traction Battery, depleting it much quicker, and forcing the Prius I.C.E. to kick in more regularly on battery recharging duties.

    I avoid this entirely by running my climate control systems in manual mode. What does that mean?

    I normally set the A/C temperature to 17c (16c when external temperatures hit 36c last Thursday). Fan speed is manually set to no more than speed 2 (I’ve used speed 3 once when I had 4 passengers in the vehicle during a 35c heatwave in 2016). Set vents to face level only, and your Prius SHOULD engage “recirculate” automatically, otherwise, select it manually.

    Before you engage your A/C life support systems, it is often wise to drive along with all windows down to dissipate the built up green house effect heat that’s built up in the cabin. Last Thursday, I used a laser probe to measure the temperature of the dashboard in front of me BEFORE I drove off after work - it was 51.4c!!!

    On super hot days, I’ll drive for a mile with all windows down, probably half of that with the A/C turned on, then windows up, and the cabin is soon chilled, despite the unrelenting solar radiation from the sun, threatened to roast my exposed skin! But - it’s cool enough to drive comfortably. Take time to reconfigure the vents to blow in your face / torso / arms / hands on the steering. The latter will surprisingly cool you down much quicker, as your hands serve in part, as biological Airconditioning condensers for the rest of your body. I spread my fingers over the A/C vents in congested traffic till my fingers are freezing cold - that cold moves up my arms and cools the rest of me pretty quick.

    Do try to use cruise control where possible, and stay in a lane where you can do so, or otherwise the traffic prefers to travel at a relatively regularly speed. Accelerating and decelerating heavily with all the boy racers in the fast lane will affect your MPG.
    I’m not saying drive like Miss Daisy - please don’t - this is NO guarantee of good MPG in a Prius. T’is but a cruel myth.

    You can hypermile, yet, more than keep up with the traffic. Indeed, on portions of my daily commute NOT governed by Average Speed Cams, I admit to rarely being overtaken, but instead, passing a lot of “slower” traffic. And I’m still using hypermiling techniques! I use CC in average speed cam zones, having calibrated my vehicles speedometer to true GPS speed. Astoundingly, on average, I’m still moving faster than a lot of the traffic; 55mph on my Prius is really 50mph in the real world (GPS). It however is dependent on what tyres you use. Your true mpg may vary.

    Lastly, long journeys generally provide better MPG. Shorter ones like an 8 mile journey may likely reduce it, depending on how hot it is, and how warm your engine was when you commenced your short journey.

    Don’t race to the red lights then brake hard. You can reasonably get up to speed then coast to a halt manipulating the throttle pedal into the “glide zone” (it’s a bit of an art, but you soon pick it up) whereby, both the ICE and electric motor are disconnected from the wheels, and you literally freewheel some distance to your intended stopping location. Brake in good time, so you can exploit regenerative braking to dump energy back into your HV traction battery - so called normal cars lose energy when they brake - but Prius owners get CASH BACK .

    Momentum. Learn to exploit momentum in the Prius - easier to do, than in a normal car.

    Get up to the speed you want quickly, then hold it in place. Travel at the same speed for best fuel economy. Be very light on that throttle once you’re at the speed you want to attain - and mostly, you’ll be surprised to discover “Gladis” will keep flying along at your chosen speed without you keeping the pedal to the metal. Plan ahead, so you can exploit regenerative braking, work out which lanes flow best in congestion on multiple lane highways, and always enjoy the ride.

    I call my Prius “The Spaceship”. You’ll soon find out why

    Once again, welcome to Prius Chat!


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  17. DLC82SV

    DLC82SV Member

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    I reset mine for you when I last filled up. I'm getting over 50 mpg and that's going up and down mountain passes. 20180720_160146~3.jpeg

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  18. DLC82SV

    DLC82SV Member

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    So the speed limit is like 75 I'm in my Prius in the left lane doing 90. This hillbilly tail gating me in a pickup must not have had a speedometer. He gets out in the right lane to pass me not realizing his vehicle is already being pushed far too hard. He just figures I'm driving a Prius, I'm must be holding him up. (He has something to prove to me of course.) Anyway he got his diesel truck out next to me to try and "roll some coal" on my Prius and mashed the throttle real hard and oil started pouring from his exhaust pipe and his vehicle began to slow. Fortunately my Prius still had some pedal left and I didn't even get any oil on my windshield. I just had to loop back around and ask if he needed a ride. Of course he wouldn't acknowledge that I one the race that I wasn't even aware we were having, nor was he willing to be caught dead riding in a Prius. Stupid is as stupid does...

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  19. DLC82SV

    DLC82SV Member

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    Those tires needed to stay fully inflated as they cause more rolling resistance when under inflated. Lucas reduces friction in oil & fuel. Could have older worn bearings holding you back. It could be your style of driving, road conditions, quality of fuel and amount of ethenol in it. Traction battery could be over working the motor generators. So many possibilities... Best of luck & welcome to Prius chat!

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  20. Data Daedalus

    Data Daedalus Senior Member

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    I just read this again, and laughed my head off, metaphorically speaking of course. This kind of behaviour from your average Neanderthal behind the wheel of some overhyped car / truck / thing with wheels is what many a contented Prius pilot has to put up with, day after day after day.

    Usually, the cause of the problem is grinding ignorance mated to a very low IQ - creating a uniquely hybrid form of pathological stupidity.

    If I had a fiver for every time during my commute, my 2008 Prius Tspirit was singled out by some motoring flash Harry, for being dangerously overtaken, cut up or just insidiously tailgated, I’d be a millionaire!

    The result is usually the same, unless I spot them a mile off, and take effective countermeasures to avoid them and their atrocious / fatalistic driving streak.
    The result is that dimwit trying frantically to overtake my Prius on the wrong side of the road, sure that he’ll complete the manoeuvre because “Prius are slow, innit?”........literally ends in a massive fail. Heavy braking when he realises the Prius goes up hill as fast as it can go downhill, and he can’t slip in front of it! I’m on Cruise Control by the way, so it’s not like I sped up to cut the dumkopf off . I’d never do that normally.

    I hate holding traffic up. I’ll normally get out of the way......but not when we’re ALL stopping in 200 metres, and my lane is the only one moving on a 3 lane heavily congested highway - and snobbish Flash Harry in his “Bullingdon BiTurbo” () just keeps trying to get up my rear end, because he cannot bear to have what he perceives to be a 15 year old Prius (private plate 5 years older than the car) apparently dawdling (it isn’t) in front of him.

    There are those that change lanes dangerously when they see your Prius cruising down the lane they want to squeeze into. Normally, they wouldn’t do that to any other car. But.....the Prius is allegedly “slow” (no it isn’t...), so it’s okay.

    Fortunately, I tend to drive like they’re not there, and often scare the living daylights out of them by NOT decelerating IF they shoved themselves callously in front of me. You can see their widened eyes in their rear view mirrors, watching me approach behind them, waiting for the expected impact. It never happens in the end, but they usually learn not to do that again in a hurry.

    Other bullies trying to cut me up, have been known to swing back into their own lane to avoid being torpedoed by my Prius. I do not suffer fools gladly.

    However, on a free multi lane highway, if I spot “Concorde on wheels” coming up behind me, I’ll happily get out of their way and let them zoom past - assuming I’m not already cruising along in a calmer lane, leaving them free to break the sound barrier and pickup a speeding fine or two!

    Here in the UK, the nicest bit remains taking off from a standing start, when some unsuspecting dullard in an equally dull eurobox (with a 1.6 litre engine) thinks he can leave an “OLD” Prius behind in his dusty wake.

    They ALWAYS get owned - up to the speed limit of course, when I get into my cruising lane and kick in CC. What? Me race? Never!


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