1 Year / 14,400 Miles / 70Mpg: Mission (Nearly) Accomplished

[Ten Ninety]

This week marks my first anniversary of Prius ownership. According to my Fuelly logs, the car has returned a nice round average of 70.0mpg over that period of time. I'm happy with that. It's not a particularly impressive figure in itself; I don't doubt that some nasty agrarian diesel rattler could be coaxed a lot higher than that, at least before the injectors failed and the DMF destroyed itself. But I've achieved my figure whilst having the pleasure of driving what has turned out to be the smoothest and most relaxing car I've ever owned.

When I bought the car, I was hoping to prove that it is actually possible to achieve the manufacturer's figures for a hybrid car without resorting to American-style pulse-and-glide hypermiling. I was doing this primarily for my own commuting entertainment but also to demonstrate the lead-footed ineptitude of the motoring press who seem insistent that hybrid manufacturer figures are purely smoke-and-mirror EU-cycle fantasy. I have, of course, technically failed as my 2010 T-Spirit is rated at 70.6mpg. However, I reckon I'm just about close enough to have made the point that these cars can deliver the goods if you take the time to learn how to drive them and your journeys don't consist entirely of very short shopping trips or 90mph motorway Audi-chasing.

I'm not entirely sure what trying to prove that particular point says about me as a person. I suspect it's not indicative of having a life full of... well, just having a life really. However, for anyone else sad enough to be interested then the Fuelly Badge below should link to the logs - I have recorded the on-board MFD figure for each fill-up as well to show how accurate (or not) that reading tends to be.

[Grumpy Cabbie]

Impressive considering the cold starts and traffic. I guess the flatter, quieter roads around Norfolk and Suffolk will help, but even so it's a good average, especially considering it's a medium sized PETROL AUTOMATIC car. I doubt any other automatic transmissioned car will come close and even similar sized diesels will struggle to average 70 mpg. Cold weather will kill their economy as the engine will never get warmed up?

[OldSkoO1]

wow

all i can say is congratulations, i honestly don't know how you did it. Incredibly to achieve the manufacturers average over an entire year!

I have been driving a prius+ which is my wife's current company car and i was thrilling to get nearly 60mpg on my commute. I tried really hard and with a warm engine i hit 70mpg briefly about 20 miles in but i couldn't hold it. So well done.

You haven't failed you have probably achieve one of the best long term averages in the UK for your car!

[Joseph D]

I don't know if I agree with you that it is not an impressive figure (even in and of itself!) I'm impressed.

I've been improving my economy figures - just about to break 60 mpg on my lifetime average (running average** = 60.9 mpg). My worst tank was 55.2 and my best was 65.9. I have to admit, though, I've been trying to get good figures as of late. I'm only 6 months in, but doubt I'll get anywhere near 70 within the next 6 months.

Flatter terrain does help. I used to live in a suburb up a hill and achieved between 55 and 59 mpg now I get 56 to 65 (so far). i'm sure there are other factors too.

Congratulations on your achievement, and if that doesn't shut Clarkson up, nothing will. Keep up the good work.

** Running average = average of last 10 fill ups.

[Cyker]

Woo! Well done mate

It is a testament to your discipline and driving ability that you managed to average that over a whole year! Most people are pretty happy if they can get that on a single tank, but over a whole year is pretty a tricky challenge!

I think my average is about 60 or so atm; I've done better in the past but the temptation to accelerate away from junctions and also overtaking, not to mention hooning about twisty A-roads on the weekend for fun, is wrecking my score

Care to share some tips and techniques for others seeking to beat their mpg scores?

[Ten Ninety]

Some further observations:

Those 14,400 miles have been driven almost entirely on the same route and it is definitely a route which is conducive to hybrid driving. My commute takes me from west Suffolk into north Essex and back. It's a journey of 31-32 miles depending on which route I follow but whichever way I go it's mostly A-road and B-road single carriageway with stretches of stop-start traffic-light town congestion at one end in the morning and at both ends in the evening. There's a couple of miles of dual-carriageway in there as well. The terrain is rolling hills rather than flat but there are only two hills which could be considered steep. The speed limit is also highly variable, with quite a few 30-limit villages and 40-zones.

We have had a mild winter this year which will undoubtedly have helped the average significantly; I travel quite early in the morning but have still only seen sub-zero temps on a handful of occasions. The car is also garaged, so I don't have to worry about defrosting/demisting before setting off, which for some people will be a significant drain on economy if they have to leave the engine running.

In terms of techniques, the following are what I have found to be successful.

• Running 40psi tyre pressures all round. I've done this in cars for years to improve steering response and even out tyre wear. It also benefits economy significantly.
• Constant forward planning to minimise braking e.g. maintaining a substantial gap from the car in front to soak up their binary-throttle speed variations. Acceleration is what knocks mpg. The less you brake, the less you need to accelerate afterwards.
• Coasting down early to junctions and lower speed limits. In fact, coasting as much as possible using very gentle pressure on the throttle to prevent regeneration.
• Using Eco mode permanently. This makes the throttle much easier to manage, once you get used to the lack of response. I never touch the EV mode button unless I want to move the car on the drive without starting the ICE.
• Using aircon all the way through the summer to keep cool as it makes the grand sum of NO difference whatsoever in my experience. However, unless it's really cold in winter I do leave the heater off for the first part of my journey home as I'm stuck dead in traffic and the ICE will just run constantly to provide heat if I switch it on.
• Using the HUD eco meter to maintain awareness of throttle position and staying away from the Power zone at all times, even when pulling away from stationary. I am patient at junctions when pulling out - I'll wait for a gap which doesn't require me to mash the throttle, unless there are folks waiting behind me. However, I have found that accelerating 'briskly' (i.e. with the eco meter just underneath the Power zone) is better than dragging it up to cruising speed on minimal throttle.
• Not exceeding 65mph on dual-carriageways and not exceeding 50mph on NSL single-carriageways. The latter is probably the only controversial aspect of my driving as I'm 10mph below the limit and people have to overtake if they wish to pass. However, on my route I can justify it because it is never long before we catch up a lorry or pensioner travelling at <40mph, meaning my responsibility for anyone's delay is temporary. If there's nobody behind me at all, I won't maintain a constant speed but will instead let the terrain have more of a say i.e. letting the speed drop right down when going uphill and letting it run higher when descending.

There's nothing radical here at all in my view but equally I fully appreciate that not everyone would be comfortable driving the same way. For me, having bought an economical car, I'm happy to try to get the best out of it by driving economically.

Anyway, for my next experiment... I intend to find out just how much of a difference wheels and tyres can make to fuel efficiency. I've been running the standard 17" T-Spirit wheels with Michelin Primacy tyres (C-rated for economy) up until now. However, I've just ordered a set of 15" alloys and will be fitting Goodyear Efficientgrip Performance tyres which are B-rated. As my commute and driving style will remain the same, I should be able to isolate the wheel/tyre impact quite clearly.

[Ten Ninety]

Initial update on the new wheels and tyres: Inconclusive!

For three weeks I ran the 15" wheels and Goodyear tyres at 40psi and achieved weekly averages no better than I was hitting with the 17s. For the last two weeks I have been running the Goodyears at 45psi and have seen some more pleasing figures but it's too early to draw any real conclusions.

I did see an all-time record filling up today of 81.6mpg on Fuelly over 332 miles. However, I suspect that's got nothing to do with the smaller wheels and in fact something is amiss with that figure, because the on-board display was only showing 81.1mpg. I'm not quite sure what's happened there. Previous Fuelly spikes have usually come when I've had to use a different pump which won't allow the same 'brimmage' as my usual pump. However, today I did use my usual pump, which was what I used last week as well. I'll have to see what happens next week - if I'm back down in the 60s again then I'll know there was a problem with today's fill.

There has been a reduction in noise with the smaller wheels, which is pleasing, although road noise is still far louder than it should be for a car of this size. Ride comfort is noticeably better, at the expense of stability and roll in corners. However, 45psi has actually improved that quite nicely and bumps are still absorbed better than the 17"s used to manage at 40psi.

I will see how things pan out in the longer term but for the time being making my car look like a shopping trolley has just about delivered the rewards I was hoping for (noise was my big hope and it has improved that). I wouldn't quite go so far as to recommend it for others yet, though.

[Julian30]

Thanks for the info, very interesting.

[GreenJuice]

An excellent achievement and a very good summary of the most conveniently attainable methods being discussed on other websites. IMHO, good judgement and timing makes the greatest difference and your record shows you have it in spades! Well done!

You didn't mention minimising weight carried, but I suspect you are doing that anyway. If you are allowing your speed to bleed off on inclines and increase on declines when there is no one behind you, then in reality you are only one step away from P&G. You will have developed enough 'sensitivity' in your right foot to do this.

There are many posts on new tyres not achieving expected gains initially. You will almost certainly see improvements as they wear in a little more.

[Chris Dance]

Very good achievment. I am getting 65.9 MPG at the moment on Tesco fuel. I do get a better consumption figure using Esso. Poorest figure I ever had was 59.9 MPG.

[Duffryn]

Ten Ninety - don't think you mentioned cruise control in your summarising - do you use or avoid? My feeling is that my fuel consumption seems to increase when c/c is engaged.

Excellent figures though, I've just about managed 60mpg over 18 months usage, with, like you, very very limited use of the POWER mode.

[ian rooke]

Hi I am not sure that fuelly is working out the fuel consumption correctly I have to have it set to show US settings for it to work out the mileage correctly and get it to match with what I work it out from full tank to full tank ( litres divided by 4.54 to get gallons then miles divided by gallons ) I have always thought I was doing something wrong when using fuelly as it should be easy to work out MPG it seems to go about it in a roundabout way.

[Grumpy Cabbie]

US settings = US gallons which are only 3.78 litres.

It is possible to get fuelly to use UK settings. Have you double checked your location is entered correctly etc?

[ian rooke]

Absolutely there is a banner which tells me I am in UK measurements (UK gallons,miles,pounds) I Have had a Prius since 2007 and am now on a Lexus 200h (same drivetrain as the Gen3 but 40 Kilo heaver) I have always had good mileage from all of them but always 5 to 8 MPG less than manufactures stated mileage I always take a full tank to full tank measurement to make sure what in on Fuelly is correct.

[Ten Ninety]

Ten Ninety - don't think you mentioned cruise control in your summarising - do you use or avoid? My feeling is that my fuel consumption seems to increase when c/c is engaged.

I don't use it on my commute at all. It's not the sort of journey where it would be appropriate. It would certainly cost me mpg if I did try to use it, as it wouldn't let me bleed off speed on inclines and would waste energy on slowing me down with regen when I was descending.

However, I do use it when on longer motorway journeys. In that situation I have found the actual speed you travel has significantly more impact than whether you use cruise or not. If I'm not in a hurry, I can tuck in a safe distance behind an HGV, set the cruise to match them at 56mph and - at this time of year - see ~80mpg on the MFD. Driving without CC in this scenario might well allow even higher figures but when I've tried it manually I haven't actually seen any better figures and it's way more tiring.

Hi I am not sure that fuelly is working out the fuel consumption correctly I have to have it set to show US settings for it to work out the mileage correctly and get it to match with what I work it out from full tank to full tank ( litres divided by 4.54 to get gallons then miles divided by gallons ) I have always thought I was doing something wrong when using fuelly as it should be easy to work out MPG it seems to go about it in a roundabout way.

Not sure what you mean about a roundabout way - it's always matched any manual calculations I've done without having to faff around with US settings. The inconsistencies I see have come from the fact the different pumps have massively different sensitivities to clicking off when full.

[PeteB]

... The inconsistencies I see have come from the fact the different pumps have massively different sensitivities to clicking off when full.

also, if you use a different service station, the slope of the forecourt can make a massive difference.

When I lived in Luton and worked in London, I often filled up a a Gulf station near the intersection of the M1 & M25 which had a very steep diagonal slope, angled downwards towards the front right of the car (unless you entered the forecourt from the wrong end!).

My Gen 1 (Classic) Prius had the fuel filler on the right, and it meant I could get an extra gallon or so in compared to a level forecourt, but when I filled a Gen 2 there (which had the filler on the left, as does the Gen 3) I could get about 2 extra gallons in - which meant I could often go about 200 miles before the first bar of the fuel gauge disappeared!

I also liked this station because they tended to be the cheapest I went past, and they always priced to whole pence, not .9 or .7.

[Nicolai]

All right: I can see that my best (recorded) average on a full tank so far, 60.69 MPG, is nothing to write home about. My all time recorded average so far is 51.84 MPG.

Constantly trying to improve it. I have my rear tires inflated to 2.5 bar / 36.3 psi and front tires to 37.7 psi.

It's the Touring sports though, not the Prius.

I must say, I find it weird that the std. tires on the TS are NOR low rolling resistance tires. They're Bridgestone Turanzas 001s and not energy saving as far I know.

[FROSTYBALLS]

I must say, I find it weird that the std. tires on the TS are NOR low rolling resistance tires. They're Bridgestone Turanzas 001s and not energy saving as far I know.

Neither are the tyres fitted to RHD Yaris Hybrids - the Bridgestone Ecopia EP25 is fitted to some left hand drive versions with 16 inch wheels.

Think that some mainstream have caught up with the fuel efficiency ratings of some of the LRR tyres - eg. the Ecopia EP25 is rated C to E for fuel efficiency, depending on size.

[Nicolai]

I see. I notice that

Goodyear Efficient Grip Performance 195/65 R15 V

is rated the winner in a Danish test of summer tires for 2014. The size is the one I need, too. The Turanzas are rated 4 / 6 on RR. Same as Goodyear E.G.

Energy Saver is rated 5/6 on RR but worse over all.

Having purchased winter tires this past winter, I'm not likely to wear the Turanzas enough to justify a change in my time of ownership. That said, the durability of these tiresare, however, only rated 2/6.

http://www.fdm.dk/test/daektest-2014-sommerdaek-michelin-energy-saver-19565-r15-v

Samlet vurdering = Overall rating

Tør vej = dry roads

Våd vej = Wet roads

Støj = Noise level

Brændstofforbrug/rullemodstand = Fuel economy / rolling resistance

Slidstyrke = durability

http://www.fdm.dk/test/daektest-2014-sommerdaek-goodyear-efficient-grip-performance-19565-r15-v

[kithmo]

Absolutely there is a banner which tells me I am in UK measurements (UK gallons,miles,pounds) I Have had a Prius since 2007 and am now on a Lexus 200h (same drivetrain as the Gen3 but 40 Kilo heaver) I have always had good mileage from all of them but always 5 to 8 MPG less than manufactures stated mileage I always take a full tank to full tank measurement to make sure what in on Fuelly is correct.

It says UK Litres, not gallons, on mine.

[Bibsy]

Tyres at 45 psi? Really?

If I run my gen 2 (15" wheels) at a mere 38 psi it gets noticeably "firm", especially over the myriad speed bumps and potholes locally, and the usual dashboard rattles move up to a crescendo. If I ran it at 45psi I think my teeth would fall out.

I wonder if a Gen3 has way better suspension, or mine is utterly nadged after 100k.

[Grumpy Cabbie]

Tyres at 45 psi? Really? If I run my gen 2 (15" wheels) at a mere 38 psi it gets noticeably "firm", especially over the myriad speed bumps and potholes locally, and the usual dashboard rattles move up to a crescendo. If I ran it at 45psi I think my teeth would fall out. I wonder if a Gen3 has way better suspension, or mine is utterly nadged after 100k.

It's not you. I have a gen3 and keep mine pumped at 1 psi over recommended.

I think the serious hyper milers are happy to pump their tyres way up so as to get those extra mpg's, at the expense of ride comfort and cornering, esp cornering in the wet. Then you could encounter issues if you have a prang and your car is impounded by the Police (usually if someone is badly injured) whether it's your fault or not. If they believe your over pumped tyres could have been a part of the reason for the accident, then you're up that creek with no paddle, no life vest and possibly with no insurance.

Whilst under inflated tyres are the cause of most accidents - usually neglect by the driver, overly inflated tyres can also cause other issues.

Stick with what makes you happy. I get good mpg's just by keeping my car stock.

[Bibsy]

Well, I had my best ever run a week or two ago - a run from Louth to Cambridge. Bit of A1, but mostly country roads and no rush. A very pleasant relaxing drive and an indicated 72 on the computer. Mostly it floats between 56 and 65, winter to summer, on the computer.

Happy enough with that. Indeed, looking at "ordinary" cars to swap to, as I'm need of an update, almost always leads me instantly to "but that will double my annual fuel cost".

I can't get the numbers to work swapping to a gen 3, at least in terms of payback though.

[Ten Ninety]

Tyres at 45 psi? Really? If I run my gen 2 (15" wheels) at a mere 38 psi it gets noticeably "firm", especially over the myriad speed bumps and potholes locally, and the usual dashboard rattles move up to a crescendo. If I ran it at 45psi I think my teeth would fall out. I wonder if a Gen3 has way better suspension, or mine is utterly nadged after 100k.

I've never owned a car with what could be considered 'soft' suspension; most of my cars have had hard springs and minimal suspension travel. I traded in a Smart Roadster for the Prius! Believe me, the Prius on 15s at 45psi is still way more comfortable than pretty much anything else I've owned. It's more compliant than running 17s at 40psi. The sidewalls on the Goodyear tyres are comically soft; if you ran them at standard psi it'd be like driving a blancmange.

Tyres at 45 psi? Really? If I run my gen 2 (15" wheels) at a mere 38 psi it gets noticeably "firm", especially over the myriad speed bumps and potholes locally, and the usual dashboard rattles move up to a crescendo. If I ran it at 45psi I think my teeth would fall out. I wonder if a Gen3 has way better suspension, or mine is utterly nadged after 100k.

It's not you. I have a gen3 and keep mine pumped at 1 psi over recommended.

I think the serious hyper milers are happy to pump their tyres way up so as to get those extra mpg's, at the expense of ride comfort and cornering, esp cornering in the wet. Then you could encounter issues if you have a prang and your car is impounded by the Police (usually if someone is badly injured) whether it's your fault or not. If they believe your over pumped tyres could have been a part of the reason for the accident, then you're up that creek with no paddle, no life vest and possibly with no insurance.

Whilst under inflated tyres are the cause of most accidents - usually neglect by the driver, overly inflated tyres can also cause other issues.

Stick with what makes you happy. I get good mpg's just by keeping my car stock.

Fair point. I doubt they'd bat an eyelid at 38-40psi but 45 might well be enough to attract attention in that situation. I'm going to take them back down to 40 soon, to see if it really was the pressure making the difference or whether it was more to do with the tyres scrubbing in as Greenjuice highlighted earler.

[korat102]

I've never owned a car with what could be considered 'soft' suspension; most of my cars have had hard springs and minimal suspension travel. I traded in a Smart Roadster for the Prius! Believe me, the Prius on 15s at 45psi is still way more comfortable than pretty much anything else I've owned. It's more compliant than running 17s at 40psi. The sidewalls on the Goodyear tyres are comically soft; if you ran them at standard psi it'd be like driving a blancmange.

My Prius on its standard 16" wheels with tyres about 2-3 psi above the recommended pressure was exceedingly uncomfortable. It was jittery and sometimes hardly seemed to have any suspension at all.