MPG test

joolsveer

This week I borrowed a 2005 Toyota Prius for 24 hours and drove 88 kilometres. According to the onboard computer the fuel consumption was 4.0 litres per 100 km. I converted this to 70 miles per gallon. The trip included some Dublin city driving and suburban Dublin 7 and Dublin 15.

I had to give the car back so monitored fuel consumption on my 2003 1.6 Renault Mégane 1.6 auto over the last couple of days. The onboard computer gives 25 mpg over the last 37 miles. The cost per litre of unleaded locally is 109.9 cents. I make this to be €5.00 per gallon. On average I drive 10,000 miles per annum. A change to the Prius would save me almost €1,300 a year.

I have read that some people feel the manufacture of the Prius is not environment friendly. Should this stop me changing?

prospect

joolsveer wrote:

This week I borrowed a 2005 Toyota Prius for 24 hours and drove 88 kilometres. According to the onboard computer the fuel consumption was 4.0 litres per 100 km. I converted this to 70 miles per gallon. The trip included some Dublin city driving and suburban Dublin 7 and Dublin 15.

I had to give the car back so monitored fuel consumption on my 2003 1.6 Renault Mégane 1.6 auto over the last couple of days. The onboard computer gives 25 mpg over the last 37 miles. The cost per litre of unleaded locally is 109.9 cents. I make this to be €5.00 per gallon. On average I drive 10,000 miles per annum. A change to the Prius would save me almost €1,300 a year.

I have read that some people feel the manufacture of the Prius is not environment friendly. Should this stop me changing?

You need to do your MPG test over a far longer distance to get a true reading.

I have had my car for nearly a year now. On some trips it averages about 37MPG and on others it does nearly 50MPG. But I have been keeping a record myself and it is about 46MPG for the year.
You should do your comparisons over longer distances.

joolsveer

prospect wrote:

You need to do your MPG test over a far longer distance to get a true reading.

I have had my car for nearly a year now. On some trips it averages about 37MPG and on others it does nearly 50MPG. But I have been keeping a record myself and it is about 46MPG for the year.
You should do your comparisons over longer distances.

The comparison I made is with similar roads and driving conditions. As I pointed out I had a loan of the Prius for only 24 hours. Of course a real test should be over a longer period and distance. I feel my experience is still relevant.

prospect

joolsveer wrote:

The comparison I made is with similar roads and driving conditions. As I pointed out I had a loan of the Prius for only 24 hours. Of course a real test should be over a longer period and distance. I feel my experience is still relevant.

well, you can only work within the conditions provided, i.e. 24 hour period.

However, I am no expert on how a Prius works, but I understand that it charges the battery itself, and than at times runs from the charged battery. I am assumin it is possible that when you received the car, it was fully charged, and that it operated on mostly the batter, but possible the next 88Km's were far less economical as the car had to recharge.

But, that is purely an assumption based on the offical combined MPG figure being 54Mpg. Maybe it would be better doing your calculation based on that figure, and a long term analysis on your Renaults MPG.

joolsveer

I drove the Prius for about 200 km in total. I made sure to discharge the battery before my "test". I believe the official mpg figure for it is 65 mpg.

I have driven my Renault for 32,000 miles and have a good idea of how thirsty it can be. The figure of 25 mpg is by no means the lowest I have got from it and on a long journey on a motorway it goes up to about 38 mpg.

UK figures
Mégane 1.6
http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?id=15713

Prius 1.5
http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?id=10982

Del2005

Have there not been threads saying that the Prius only manages 45-50mpg in the real world? If you are looking for an ecomnical car get one of the small Euro diesels, they can do 50-60mpg+.

Also the problem with the total life of the Prius is the big bank of battieries that only last 100,000km/5yeards. These take a lot of energy to produce and dispose off.

The mpg isn't much better the better then a new diesel and there is a lot more energy in the production/disposal of the car. You have to work it out on this grounds. There is also the question of getting rid of a perfectly good car to replace it with a "Green" car. Why not keep the one you have till it reaches its natural end of life and then replace it with a proper Green car?

joolsveer

Diesels are known to emit more dirt into the air, cause more noise pollution and still don't give the same mpg.
There is a 160,000 km eight year warranty on the Prius hybid parts.
I believe that driving a car around Dublin and suburbs is a real world test.

Can you give me the name of a "proper green car" that I can test? I would not want to get rid of my car if it was a reliable and cost effective means of transport.

bonkey

joolsveer wrote:

Diesels are known to emit more dirt into the air, cause more noise pollution and still don't give the same mpg.

I think you need to look at newer diesels.

Unless its different in Ireland....over here, many/most new diesels are fitted with particle filters etc. which are still not common on petrol engines. As a result, they have fewer emissions per km. They also have better mpg, almost-equivalent horse-power.

An excellent example would be the Peugeot 307SW.

2L petrol : 143HP, L/100km : 10.7/6/7.7, CO2 g/km : 184
2L diesel : 136HP, L/100km : 7/4.5/5.4, CO2 g/km : 142

Over here, cars are given an efficiency rating. The diesel 307SW rates an A for its class. The petrol rates a D. I've yet to see a petrol engine in that class break class D, but I've seen several A-class diesels.

The 1.6L versions are the same story - diesel kicks petrol's ass.

Diesels are, as you say, still typically louder though.

Can you give me the name of a "proper green car" that I can test?

What size car are you looking at in terms of usage-needs?

joolsveer

I would like the car to be around the same size as a Mégane or Prius. I would not be happy to buy a European car as I have tried various cars made in the EU over the last 30 years and none of them has been trouble free.

There seems to be a bias against the Prius and I don't the reason for it. Is there empirical evidence that supports this view?

Prius litres per 100 km 5.0/4.2/4.3 CO2 g/km : 104

The Peugeot 307 2.0 HDi FAP (136 bhp) has a C rating on this website http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?id=13283 and the Prius has a B rating.

Del2005

The proper green car hasn't been invented yet. Thats why I said hold onto your own car till it's natural end of life.

If you do a search for Prius on this site and others you'll find a good few threads with stories of how people are getting better MPG outta new Euro diesels then from a Prius. The Prius was mainly designed to work for the US market where they had cars in single figures for MPG.

And to be honest a 80km drive is not a way to judge a cars economy.

There are new 1.4 common rail diesels in a lot of cars of that size that are giving much better MPG then the Prius can. And when dealing with green issues the full life of a object has to be considered, I think I heard somewhere that the Prius is much harder to manufacture and dispose of then a standard car as the big battery bank has a lot of dangerous materials in it.

One other thing to consider. If buying a car to be green then you need to keep if for as long as possible. What sort of 2nd hand market is there going to be for a car that has a load of battieries to be replaced after 160,000km. All battiers run out there will be no warrenty replacement as they are consumables, they won't replace the battery on a new car now

bonkey

joolsveer wrote:

I would like the car to be around the same size as a Mégane or Prius. I would not be happy to buy a European car as I have tried various cars made in the EU over the last 30 years and none of them has been trouble free.

There seems to be a bias against the Prius and I don't the reason for it. Is there empirical evidence that supports this view?

I'm not sure tehre is.

For example...someone earlier on this board claimed that the problem with the total life of the Prius is the big bank of battieries that only last 100,000km/5years.

A quick google shows that Toyota offer a warranty on the battery for 100,000 miles / 8 years at least. They also state that they believe it can be good for up to 15 years.

Now...this doesn't mean that the battery will last more than 10 minutes. maybe it will need replacing after 100,000km or 5 years, but I seriously doubt it. I would guess that some of those figures are FUD and/or misreporting, or are taking worst-case stories from early-edition Prius models and suggesting that this is the average / best-case.

Its worth nothing that the battery model is due to change in 2008/2009...whether or not that would influence your decision to buy one, I don't know.

The Peugeot 307 2.0 HDi FAP (136 bhp) has a C rating on this website http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?id=13283 and the Prius has a B rating.

I was comparing a petrol to a diesel, not a diesel to a hybrid.

I've no doubt that a hybrid should outperform either. The point I was making was more that if you decide against a hybrid, then I wouldn't rule out a diesel on "green" grounds.

The A and D class ratings I mentioned, incidentally, are according to whatever system is used here in Switzerland.

In terms of what's greenest for a new car, its still a tough nut...

Have a look here...might help you out...

http://www.eta.co.uk/tools/car-buyers-guide.asp

In the small-family category (wherein the Prius lies according to these guys) you'll notice it (the Prius) doesn't come in first, but it does get a top rating anyway.

311

If I was concerned about the envoirnment in a serious way and occasionally needed to carry two passangers ,I might go for the small fiat multijet diesel engine.
They are available in some other european manufacturer's cars also ,afaik.
Heres the fiat model , http://en.wikipedia.org/wiki/JTD_engine

mcaul

In that bracket, I'd try the Skoda Octavia 1.9 diesel - gives 55 - 60 per gallon and seems to hold values well. Reasonably priced too.

Friend has over 160,000 miles on one and it still goes well.

Megane / Renault are not known for fuel efficency. Buy a copy of what car and look at each manufacturer - Kia & Hyundai are other to consider esp Kia Ceed with 7 year warranty.

Capt'n Midnight

Peugeot are bringing out a Diesel Hybrid next year. So it should beat any petrol hybrid by about the same factor a diesel beats a petrol.

Also hybrid batteries are quite small. Not sure if this is to do with the FUD over us companies having patents on the use of batteries with cells larger than a D-Cell.

BostonB

Someone in the family is getting a 1.3 CDTI Astra next week, it will be interesting to see what mileage it gets vs the older 1.7 DTI. I was surprised on a recent long run in 2L Petrol Primera, it gave us 45mpg, usually in heavy traffic it gives 20~25mpg. I've seen sub 20's on a bad day. It was noticeable more efficient at 80~100km/h than 120 km/h. Are there any articles comparing a Primus with a small diesel. I would the small diesel would make better sense all round.

Lennoxschips

My father has a diesel Lancia that does 4.8 L / 100 km on the motorway. Pretty impressive really, especially when you consider it's an estate car.

Call me crazy, but one thing I do when driving is never drive with a full tank. All that extra weight.