Omg mpg (1 Viewer)

andyetan

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Sep 7, 2010
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HELP!
HI! I'm new to motorhoming and recently purchased a great little Fiat Ducato 1.9td Riviera 1000.
The only thing I'm not happy with is the consumption, I'm only getting 20mpg from it, no matter how carefully I drive. It's a 1995 lhd with 40k on the clock.
Is this normal? I thought it would be more frugal than that. Anyone else got one and getting better results?
Thanks
Andy
 

hilldweller

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HELP!
HI! I'm new to motorhoming and recently purchased a great little Fiat Ducato 1.9td Riviera 1000.
The only thing I'm not happy with is the consumption, I'm only getting 20mpg from it, no matter how carefully I drive. It's a 1995 lhd with 40k on the clock.
Is this normal? I thought it would be more frugal than that. Anyone else got one and getting better results?
Thanks
Andy

Our 2003 2l JTD manages 25, but no better.
 

pappajohn

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Aug 26, 2007
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26mpg at 55/60mph on mixed roads from our 2001 2.8ltr ducato.

10mpg from our 6.8ltr V10 rexhall rv at 50mph (motorway) :Eeek:

your 1.9ltr will be working much harder than the 2.8ltr to do the same amount of work.

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fugglestick

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Jul 24, 2010
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Help mpg

HELP!
HI! I'm new to motorhoming and recently purchased a great little Fiat Ducato 1.9td Riviera 1000.
The only thing I'm not happy with is the consumption, I'm only getting 20mpg from it, no matter how carefully I drive. It's a 1995 lhd with 40k on the clock.
Is this normal? I thought it would be more frugal than that. Anyone else got one and getting better results?
Thanks
Andy

The easiest way to decrease fuel consumption is to slow down. When you double the speed of a vehicle, you need 8 times the engine power!!!!. Your engine is working a lot harder than a larger one, so 45-50 will be a lot more economical than 50-60. Just enjoy the scenery more....
:thumb:
 
May 16, 2010
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The easiest way to decrease fuel consumption is to slow down. When you double the speed of a vehicle, you need 8 times the engine power!!!!. Your engine is working a lot harder than a larger one, so 45-50 will be a lot more economical than 50-60. Just enjoy the scenery more....
:thumb:

Sorry fugglestick but your premise is wrong......slowing down would increase the consumption.....mpg is about revs over weight....its about lowering the depression in the manifold and therefore the fuel ratio mixed with it::bigsmile:
The depression increases towards idle and when you accelerate hard the balance is roughly 2500 to 3500 rpm
 

dave newell

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Oct 31, 2008
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Sorry fugglestick but your premise is wrong......slowing down would increase the consumption.....mpg is about revs over weight....its about lowering the depression in the manifold and therefore the fuel ratio mixed with it::bigsmile:
The depression increases towards idle and when you accelerate hard the balance is roughly 2500 to 3500 rpm

Sorry to disagree Mr Strange but Fugglestick is right and you are talking nonsense! For a start the manifold depression you mention only occurs in a petrol engine and your final comment just doesn't make any sense at all. The engine speed that is most economical will vary from one vehicle to another as it depends on the engine's state of tune, the aerodynamics of the vehicle its pulling and the overall gearing.

To the OP low 20s would be my guess for a 1.9TD of 15 years vintage pulling a small coachbuilt bodied motorhome. The engine is on the small side and trying to push a vehicle with the aerodynamics of a small block of flats through the air. 50 to 55MPH is generally regarded as the best compromise of a decent travelling speed and acceptable fuel consumption.

D.

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welsh winger

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Jul 7, 2009
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I have a 1.9td fiat, well till Wednesday that is, that another story, the first couple of times I used it, I was only getting 20 mpg, over the 12 months of ownership this did improve to 25/26mpg, why? I started using shell petrol rather than the supermarkets offering, every other tank I used the diesel version of redex.

The main thing is as a driver you get to realise that slamming your foot to the floor is pointless, the van will get to speed in its own time, following on from acting strange saying its revs vs weight, on smaller engines the torque comes from a relativity high revving engine, which creates a small power band, like a 2 stroke engine, oh yes a diesel is a 2 stroke it "fires" every other stroke.

In short use good fuel/redex, service the van a good quaintly oil will help, lastly and a simple answer to high consumption, are the brakes binding? lot of motor home owners don't use the van from one month to another, and expect to jump in it and away to go, sorry does not work that way. when I bought the 1.9td I spent a few hours cleaning and overhauling the brakes, which was well worth the time taken, better brakes and knowing they were not binding.

There is a few points in my answer that may inflame other debates, the shell diesel for example, I personally have proved this to be true, on my van, car and motorbike, fuel consumption goes up when you use it, the van produces less smoke on start up, the bike goes like a scalded cat when on shell but hesitates on supermarket fuel, my car I have only had a month but has not had any other fuel in it from my personal experience, try it yourself.

The torque question is simple higher revs create the torque, hence the smaller engined vans are often noisy and screaming their heads off, larger engines even non turbo are a more relaxed engine relying on the torque the engine produces, smaller engines work harder and use more fuel.

I am picking up a 2.8 fiat on Wednesday, when I test drove it, I found that other than more torque the speed in the gears was not that different, the way it went up hills was very different, all down to torque.

I expect a few comments disagreeing with this post, but as I have said this is my personal findings over owning 4 motor homes 2x 2.5D the 1.9td and now the 2.8D

I need a lie down after this epic :ROFLMAO:

Nick
 

scotjimland

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Jul 25, 2007
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Optimal driving speed ?

Those with fuel computers will know when they are driving at the optimal speed for best MPG .. those without it is a case of trial and error..

I have trying to establish the best motorway cruising speed for my Honda CR-V .. I haven't come to a firm conclusion but over 65 it drops dramatically. So far the trial would suggest that it's between 55 and 65 .. higher or lower speeds reduce my MPG. but all vehicles have a different optimal speed. Finding it is the tricky part. !

In order to better understand why, I searched and found this article that explains it..

How Stuff Works

An extract ...

If your car is going 0 mph your engine is still running. Just to keep the cylinders moving and the various fans, pumps and generators running consumes a certain amount of fuel. And depending on how many accessories (such as headlights and air conditioning) you have running, your car will use even more fuel.

So even when the car is sitting still it uses quite a lot of fuel. Cars get the very worst mileage at 0 mph; they use gasoline but don't cover any miles. When you put the car in drive and start moving at say 1 mph, the car uses only a tiny bit more fuel, because the road load is very small at 1 mph. At this speed the car uses about the same amount of fuel, but it went 1 mile in an hour. This represents a dramatic increase in mileage. Now if the car goes 2 mph, again it uses only a tiny bit more fuel, but goes twice as far. The mileage almost doubled!

Efficiency of an Engine
In effect the efficiency of the engine is improving. It uses a fixed amount of fuel to power itself and the accessories, and a variable amount of fuel depending on the power required to keep the car going at a given speed. So in terms of fuel used per mile, the faster the car goes, the better use we make of that fixed amount of fuel required.

This trend continues to a point. Eventually, that road load curve catches up with us. Once the speed gets up into the 40 mph range each 1 mph increase in speed represents a significant increase in power required. Eventually, the power required increases more than the efficiency of the engine improves. At this point the mileage starts dropping. Let's plug some speeds into our equation and see how a 1 mph increase from 2 to 3 mph compares with a 1 mph increase from 50 to 51 mph. To make things easy we'll assume a, b and c are all equal to 1.

You can see that the increase in power required to go from 50 to 51 mph is much greater than to go from 2 to 3 mph.

So, for most cars, the "sweet spot" on the speedometer is in the range of 40-60 mph. Cars with a higher road load will reach the sweet spot at a lower speed. Some of the main factors that determine the road load of the car are:

Coefficient of drag. This is an indicator of how aerodynamic a car is due only to its shape. The most aerodynamic cars today have a drag coefficient that is about half that of some pickups and SUVs.
Frontal area. This depends mostly on the size of the car. Big SUVs have more than double the frontal area of some small cars.
Weight. This affects the amount of drag the tires put on the car. Big SUVs can weigh two to three times what the smallest cars weigh.
In general, smaller, lighter, more aerodynamic cars will get their best mileage at higher speeds. Bigger, heavier, less aerodynamic vehicles will get their best mileage at lower speeds.

If you drive your car in the "sweet spot" you will get the best possible mileage for that car. If you go faster or slower, the mileage will get worse, but the closer you drive to the sweet spot the better mileage you will get.
 

Jim

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Jul 19, 2007
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On a motorway, all things being equal, If I stay at a steady 54mph I get 9.9mpg. Travelling at 65 I get 7.5mpg, sometimes less.

On a 3000 mile round trip in my RV, it pays to have a light right foot. :Smile:

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Wow

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Sep 8, 2010
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Your MPG is dire, we have and old N reg 2.5 on a 8.5m exhibition van and do much better than that :Sad:.
Dave Newel is 100% right in what he's saying, take his advice along with Welsh Wingers about Shell and find you sweet spot as mentioned in ScotJimLands informative article and you will see improvement i'm sure:thumb:
If you've done and its still bad, above all don't let it spoil your fun, just do slightly shorter or better planned journeys.

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shortfuse

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Apr 9, 2008
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Hi Andy
Our 1.9 td averaged 24 mpg ( measured over about 8000 miles )
usually driving around 55 / 60
regards sf
 

656

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Hi

Sounds like a Re Map could help with the Torque. With the money back guarantee from WOW Tuning you have nothing to loose.
 

DESCO

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Had 1.9TD Fiat Swift Sundance but only for about 1 year (another story) and the best we could get was 23/24Mpg never got better.



Dave :thumb::thumb:
 
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Issie52

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We have had our 1.9 for 6 years and we get 30 mpg in ours ,we do put ametech Restore in with every fill up. Done over 55.000 km in it since we got it and it runs great.

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Jul 13, 2008
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I have a 1.9td fiat, well till Wednesday that is, that another story, the first couple of times I used it, I was only getting 20 mpg, over the 12 months of ownership this did improve to 25/26mpg, why? I started using shell petrol rather than the supermarkets offering.
Nick
You used PETROL! no wonder your MPG decreased......;)
 

Debs

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The search facility is very good on the forum..........this thread is 6 years old;) (y)......
Wonder if his mpg improved though:LOL:

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Feb 9, 2008
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Slow down, take it easy, that will save fuel, after all you are on holiday!
 

Emmit

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The OP's first post was his last.

I wonder what happened, and who put him off.:ROFLMAO::ROFLMAO::ROFLMAO:
 
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On a motorway, all things being equal, If I stay at a steady 54mph I get 9.9mpg. Travelling at 65 I get 7.5mpg, sometimes less.

On a 3000 mile round trip in my RV, it pays to have a light right foot. :Smile:
Blimey......little wonder you are staying in Spain for so long. Are you saving up for the drive home;):)

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