Fifthgear "prius Vs Patriot", About Same Gas Milage?

[joniro]

http://fifthgear.five.tv/jsp/5gmain.jsp?mn...amp;pageid=2848

The result

Had we relied on the onboard computers, the Prius would have won by a landslide, as by the end of the trip they read 57mpg and 42mpg for the Prius and Jeep respectively.

However, to get the real figure, we calculated consumption based on how much fuel each car had used over the 160 miles. The result was astonishing: both cars had used nearly identical amounts of fuel. The Jeep had averaged 38.9 mpg - only 3.1 mpg less than its computer had recorded. However, the computer of the Prius appeared to be telling whoppers: it actually achieved just 39.9 mpg - a massive 17.1 mpg less than it had claimed.

This is strange.. Was there something wrong on this Priuses onboard computer. I can't ever get 4.1l /100km (57mpg) in a similar drive that they claim they did on this test. I do 5.1l/100km and I dont think my computer is lieing (maybe 4.9l/100km if i'm especially carefull)

- Joakim

[mrhappy]

I read with interest... I am a new owner 07 prius... recently [yesterday] tested my onboard computer fuel consumption for a 2week period. I traveled an 80 mile round trip via the motorway average speed 60-70, the rest in and around the town [plenty of hills and traffic] aprox total 365 miles.

the computer registered avarage 52 mpg :) i refilled at same petrol station and calculated manualy 51 mpg :D as a new owner i used all the gadgets... B [option for slowing down], ev button from standstill. it seemed to me that the person driving in the fifthgear test may not of been A1 with all the gadgets! do the 'B' and 'EV' make any difference? is this car made for motorway miles? or is it a towny? what does anyone else think?

Really Happy owner

[timberwolf]

I read with interest... I am a new owner 07 prius... recently [yesterday] tested my onboard computer fuel consumption for a 2week period. I traveled an 80 mile round trip via the motorway average speed 60-70, the rest in and around the town [plenty of hills and traffic] aprox total 365 miles.

the computer registered avarage 52 mpg :) i refilled at same petrol station and calculated manualy 51 mpg :D as a new owner i used all the gadgets... B [option for slowing down], ev button from standstill. it seemed to me that the person driving in the fifthgear test may not of been A1 with all the gadgets! do the 'B' and 'EV' make any difference? is this car made for motorway miles? or is it a towny? what does anyone else think?

Really Happy owner

I suspect engine braking has been discussed many times before and in normal driving you shouldn't use it. Have a look at the following link http://www.artsautomotive.com/PriusEngineBrake.htm and in particular pay attention to the second block of text and what it says when the HV batteries are full and then the system has to switch on the petrol engine to perform the engine braking.

The main TV programmes (Top Gear and Fifth Gear) always seem to concentrate on how fast a car will drive around a racing track, I presume that is to simulate typical UK motorway driving

[Boro Sera]

The main TV programmes (Top Gear and Fifth Gear) always seem to concentrate on how fast a car will drive around a racing track, I presume that is to simulate typical UK motorway driving

If they were trying to simulate typical UK motoring driving then they should crawl along in 4 MPH jams for hours ( especially when it's sunny ! ) and on the occasions where they manage to find a free moving stretch of road they should conserve fuel by tailgating someone to reduce drag ! :P

[hertsnminds]

it seemed to me that the person driving in the fifthgear test may not of been A1 with all the gadgets!

Maybe they should have had a word with Tiff, as in the Tiff V Trulli Prius challenge he seemed to know all the tricks for optimising MPG.

The article does also say

both drivers were to drive the way they normally would,

So no optimising techniques were used.

[praeter]

http://fifthgear.five.tv/jsp/5gmain.jsp?mn...amp;pageid=2848

The result

Had we relied on the onboard computers, the Prius would have won by a landslide, as by the end of the trip they read 57mpg and 42mpg for the Prius and Jeep respectively.

However, to get the real figure, we calculated consumption based on how much fuel each car had used over the 160 miles. The result was astonishing: both cars had used nearly identical amounts of fuel. The Jeep had averaged 38.9 mpg - only 3.1 mpg less than its computer had recorded. However, the computer of the Prius appeared to be telling whoppers: it actually achieved just 39.9 mpg - a massive 17.1 mpg less than it had claimed.

This is strange.. Was there something wrong on this Priuses onboard computer. I can't ever get 4.1l /100km (57mpg) in a similar drive that they claim they did on this test. I do 5.1l/100km and I dont think my computer is lieing (maybe 4.9l/100km if i'm especially carefull)

- Joakim

The problem with these anecdotal reports is, you are never sure that they use a valid method for calculating the amount of fuel used. They arrive at a completely surprising conclusion and never think of checking by repeating the test. Actually they probably do think of it but the ridiculous result they publish is the one that suits their purpose. Never let the truth get in the way of a good story lads!

I check my consumption by logging the mileage and fuel used from pump cutoff to pump cutoff. This is only meaningful over a long period because the cutoff pressure varies considerably between pumps and at different atmospheric conditions. Over several months I estimate the actual mpg to be only 2 mpg below the computer.

It's worth noting that even if you fill different cars to cutoff at the same pump the inlet pipe and tank geometry play a large part in determining the back pressure presented to the pump by each car.

[timberwolf]

I do find these negative reports off putting.

I've recently watched the Top Gear, repeated on Dave (the TV channel), which showed a 2003/04 model Prius and another in 2008 about a 10 lap race with a BMW M3. The presenter claimed to commute 75 miles to London and he only got 45 mpg, protesting that he drove normally, but what does his normal mean?

I get about 32-35 mpg from my Civic 1.6 Auto, my driving style isn't consistent or not that light-footed at times, for example on short motorway journeys (7 miles) and I'll put my foot down to get up to between 70 to 80. Around town, I'll drive within or below the speed limits as my speedo reads (so technically I guess slower than the speed limits assuming the speedo over reads).

My interest isn't overly about saving the planet, and I am attracted to the Prius because of the technology and sometimes silent running, but when I see reports of the Prius only doing 17 mpg, I do wonder how badly it would do if I was driving one. I would think 45 mpg is good when you compare with my current consumption.

[Chris Dance]

Prius with only 17 miles to the gallon is utter rubbish. 50 -60 MPG seems to be what Prius owners are getting. I am getting 55.9 MPG on Tescos fuel.

Top Gear takes a delight in knocking the smaller family cars. They have to be racing everything or taking a very expensive motor and wreck it. That is not normal motoring.

Most Prius owners I know are very pleased with the all round performance of the Prius. Ignore the "Top Gear" wreckers and other "knockers".

[timberwolf]

What is normal motoring, and do the majority of Prius owners drive differently from the other groups of normal motorists?

[Rael]

What is normal motoring, and do the majority of Prius owners drive differently from the other groups of normal motorists?

Hi Timberwolf,

I drive a 2007 T Spirit. I recently travelled a 200 mile round trip with three adults on board, mostly on motorways with the cruise control set at 70mph and air-conditioning on. The result 60.5 mpg!

Ironically, had there been roadworks and other delays on route, (where the Prius would have used electric-only traction, and switched off at every stop) the fuel consumption may have been, in my previous experience, even lower!

Around town, and on A roads where cruise control is not really suitable, there is definitely an art to getting low consumption figures. (If you research the Internet you will find a lot of guidance in this.) The best one-way trip across town that I have ever recorded was 85mpg! (Engine warm, Battery fully charged, and more hills down than up!)

An example......... from traffic lights in a 30mph limit, on level road: accelerate with other normal traffic to 30mph, (petrol engine and electric motor will be used), then back-off the throttle a little and the car will "glide" on electric power only, maintaining 30mph. If the road goes down a bit of a hill you may find the ideal gliding mode where nothing is used (transmission still in Drive mode): the power display will show no Battery power or petrol engine activity! Alternatively dependent on the gradient the Battery may start to be recharged by the car's gained momentum, and any braking will recharge the battery further. Of course in the end if the battery is depleted the petrol motor will have to come on for a while to effect recharging.

In practice the usual cut and thrust of driving will mean that extra acceleration where the petrol motor will cut-in is needed between gliding phases, and I find that this generally keeps the battery topped-up. In no way is one impeding general traffic flow by driving like this, and it becomes second nature in the end, and reaps the benefit of excellent fuel economy.

The car will glide on electric power, and no power sometimes, at 50mph and higher (dependent on road conditions) just by the sensitive use of the throttle.

Using the method above, it is not necessary to keep engaging the EV (Electric Vehicle) button, or applying the B mode on the gear selector (you will find a lot of misinformation about these from Toyota salesmen, and on forums!)....just put the car in Drive and glance at the energy diagram on the screen from time to time to see how your throttle applications are affecting things. In the end you get to feel what is happening, and need less and less recourse to the screen.

If you haven't already done so, do take an extended test drive, and see for yourself that with an educated right foot, very low fuel consumption can be attained, without being an obvious "slow-coach"!

Finally you will find that even taking the fuel-consumption out of the equation, the Prius is a lovely car to drive.

I hope this helps ................ Rael.

[Habu]

My average overall is mid 50's which I'm really pleased with especially after my last car, an 07 Civic Type R GT would often dip below 20. On a motorway cruise, travelling along in no rush at about 65mph and with a light throttle I regularly get into the mid to upper 60's mpg :) and once averaged almost 100mpg over a 20 mile run. My yellow mpg bars (if you know what I mean) were practically completely full right across the screen.

It's hard not to like a Prius :D

[Mkuk0]

Rael

Nice description, well put, very heplful!

[tjones7]

To be fair to Top Gear, when they did the M3 vs Prius test they drove both flat out the whole time. Jeremy Clarkson then made the point that he wasn't saying that an M3 is more economical than a Prius, but fuel consumption is affected by how you drive and if you drive flat out, fuel consumption will fall.

He was trying to point out that you if you cannot afford to buy a newer, more economical car, change your driving habits.

[timberwolf]

Thank you Rael for a very detailed post. It doesn't sound like you drive normal though?

Various articles. the Fifth gear link at the of this thread, the one by the paper driving to Europe, and JC's 70 mile commute to London, all chaimed to be driving normally and achieved low 40 mpg. What were they doing that achieved those results? Can a Prius only drive up to 70 mph, and does its technological advantages stop being worth while at 71mph?

You are correct that I should try to get an extended test drive - how does a private motorist get more than a 15 minute test drive?

Sorry tjones7, I don't see anything fair in devising tests that ensure that the Prius will look bad there's no balance, a few quietly spoken words doesn't compare with the visual impact of the driven footage and conclusion of the test. Hardly, a balanced report, and yet agian the question why does their view differ so much from the owners here?

[hertsnminds]

how does a private motorist get more than a 15 minute test drive?

My local Toyota dealer gave me a whole weekend test drive of my Verso before I bought it. If a dealer wants to sell you the car they will let you have an extended test drive.

[Rael]

Thank you Rael for a very detailed post. It doesn't sound like you drive normal though?

Hi again Timberwolf....

You are right to conclude that for getting the best mpg from a Prius, one does not drive it like perhaps the majority of people normally drive at the moment. The usual fuel economy tips that some people apply when driving an ordinary car, are equally relevant to the Prius, but it also has the enhancement of battery traction, which gives an extra level of economy, if consideration of it’s needs is given when driving.

In essence, like any other vehicle, the further the throttle is pressed down, the more fuel is used.

I have no experience of cruising at above 70mph, but of course this would increase fuel consumption, over that achieved by cruising at a lower speed. My figures are all given as when complying with the national speed limits, although of course any journey may present situations where transient speeds in excess of this may need to occur, and the Prius still accelerates strongly above 70mph.

If the majority of journeys are made at motorway speeds, (and we all know that at times the general traffic flow exceeds 70mph) then a diesel may be a better choice. I have had several diesel cars, and must say that I prefer the Prius: it is smoother and quieter in operation, and for me has better fuel consumption.

Regarding a test drive; if your local Toyota dealership is serious about selling you a car they will let you have a demonstrator for an evening, or even a week-end (just ask…they don’t usually volunteer those options!) That is what I did before making a purchase.

I will be very interested to hear your impressions after such a test.

Best wishes … Rael.