Fuel Consumption

Happywanderer · The Master

RE: Fuel Consumption

Boroma577 · Guru

Happywanderer wrote:
They are small truck tyres boroma.

Whats GVM??

HW, if the wheels & tyres are smaller than what the vehicle manufacturer recommends then yes, you will use more fuel.

The GVM is the Gross Vehicle Mass....the weight of Myrtle all up.......loaded complete with fittings, food, kitchen items, clothes, water, camp gear, manchester, hoses, spares, tools, awning etc....everything in other words.

I suspect she is a wee bit heavy and and old girl to boot.

Happywanderer · The Master

I wouldn't have thought the tyres would be too small would they boroma?

Would have no idea how much her total weight would be. She's equipped with wooden cupboards down both sides. One side carries the sink, stove, gas bottle on the outside and food.
The otherside carries the wardrobe, another cupboard with electrical stuff, and the fridge. Plus under the bed/seat carries fold up table and chairs.
Then all the other stuff, like portable cooker, water hoses etc. I suppose it all adds up.

rockylizard · Guru

Gday...

I would assume that given the Myrtle's aerodynamic shape (or lack thereof biggrin ) and the weight that she is carrying, 14-16ltr/100km at 90kph on the open road would be pretty fair and reasonable.

As others have advised, try upping the tyre pressures (eg 36psi to 40psi all round) and then drive at 90kph to Geelong and then try 85kph on the way back. You will probably be able to "feel" the difference in her responsiveness.

I would suggest you fill up before you leave Echuca and do not fill up until you get back to Echuca. Don't fill at Geelong as 100km is not sufficient distance to get a fair indication of consumption.

It is usually wisest to fill the tank - taking notice if possible of where the fuel level is in the fuel filler pipe, drive it until about a quarter of tank remains, then refill it to the same level you did at the beginning.

Using the consumption achieved over short distances (and even 100km is a short distance in this regard) will give perhaps a 'distorted' indication.

Fuel consumption will vary over different road surfaces, influenced by wind direction and velocity, hills (and all hills are different on different roads), how much braking you do and obviously how often you need to accelerate back to cruising speed, the temperature of the day (better economy on cool overcast days usually), the 'condition' of the engine and even the distance above sea level you are travelling in.

I would do my evaluation over at least three tankfulls before I formed an opinion. This will give a far better indication of actual and expected fuel consumption.

And just quietly, there is no point in comparing what people achieve with a diesel motor - there is no comparision with a petrol engine as the petrol engine will ALWAYS use more fuel for a given size of motor.

Oh yeah ...... and everyone has a different sized and weight right foot biggrin ... this is the greatest influence on fuel consumption of all vehicles.

So, hoping I have not confused the issue too much, and restating my original advice .... 14-16ltr/100km would be 'reasonable'.

Cheers

John

Boroma577 · Guru

HW, I have to say that I also agree with everything John (rockylizard) also says. He has covered in depth a lot of the items I glossed over (thanks John)

Re the tyres and wheels and it is both HW......I honestly can't say if they would be too small or not. You'd have to check what the manufacturer of Myrtle recommends. I am hoping it is listed on the inside of the door or somewhere for you to get them checked.

Mind you, the tyres & wheels are only one contributing factor.......there are many as John has also pointed out.

-- Edited by Boroma577 on Wednesday 4th of January 2012 11:11:55 PM

Happywanderer · The Master

John, its nearly 300 ks to Geelong. The 100ks I was talking about was the first part to Bendigo. I would be worried I wouldn't even make it to Geelong and definitely not back to Echuca without filling up.

Happywanderer · The Master

John, I can't drive it till a quarter of a tank remains. As I mentioned before when the gauge says empty I have found there to still be 20 litres of a 58 litre tank still in there.

Happywanderer · The Master

No John, you haven't confused the issue at all. I am now realising 14 -16 litres could be quite reasonable and as you say need to test over much longer distance to get a true outcome.
Will put more air in the tyres and check the size of wheels and tyres but sure they would have to be correct as would be the same size as she would always have had. I can't imagine anyone changing the size and for what reason.

rockylizard · Guru

biggrin Gday...

OOPS .... how stoopid of me .... I should have realised .....

If you get 16ltr/100km then it will take 50litres to do 300km - so a tankful should get you to Geelong from Echuca. I think you said you have a 58ltr tank.

So note where the fuel level is in the fuel filler pipe when you fill in Echuca, fill to that level in Geelong (or whenever you refill) noting litres it took. Then refill back at Echuca (or whenever you refill) and again fill to the same level in the fuel filler pipe.

That is therefore now two tankfulls - that calculation should give you a fairer indication of consumption. I would be fairly confident the consumption in each direction will vary - and dependent on all the conditions I stated previously, may be surprisingly different - or surprisingly similar biggrin .

It would be a good trip to estimate consumption.

Cheers

John

Esmeralda · Guru

Marj - my car (3.8L auto) towing the caravan uses 14.6L/100km (petrol) and I travel at speed limit. As you know the van is small and not heavy. I was thinking this was a bit heavy on the fuel but now am not so sure.

Ron and Shirley · Senior Member

HW

Your quoted fuel figures are a rough guide (eg around 325km/tank based on 100km of travel) but you need more data over longer distances under different conditions to get reliable figures. However it is a start.

Others fuel figures for different vehicles to yours, particularly diesel engines, are totally irrelevant and I for one cannot understand why members bothered responding, other than to get their post count up smile .

Your return trip to Geelong will give you a better guide as it is around 300km each way. Weather conditions (eg headwinds) and terrain eg (hills to climb) all come into play as well. So your trip down and then back will give you a better guide. However only after a number of long distance trips under different conditions and terrain can you get relatively reliable fuel consumption figures.

I have done this exercise with my vehicle. Just the vehicle (usually around home), the vehicle towing, and the vehicle doing serious 4WDing in the bush. It is not done from a economy aspect, as suggested by one poster disbelief , but purely to have an indication as to the distances I can expect to cover. This is particularly important with 4WDing in say the Victorian High country, and towing in the outback, where there is long distances between fuel stops.

I get my fuel figures by filling the tank such that I can see the level of fuel in the tube leading to the fuel tank and off course in my case the odometer (you use GPS thats OK). I dont rely on the bowser cut off due to foaming of the fuel as all bowsers are different. I usually fill up again when the fuel gauge indicates a bit less than ¾ used or in the case of 4WDing/Touring with the van at the town either mid trip and/or closest to the end of the trip.

BTW

For anyone interested, though not relevant to this thread

My 3L Diesel Auto Patrol

Around town 12.5L/100km

Towing 2.4 ton 18L/100km, at around 100km/hr Highway average.

Serious 4WDing, vehicle only, 20L/100km, a lot of heavy low range driving.

Edit Just saw RockyLizard's last couple of post which was made as I was responding and clearly I agree with his comments.

-- Edited by Ron and Shirley on Wednesday 4th of January 2012 11:34:42 PM

Boroma577 · Guru

Happywanderer wrote:
I can't imagine anyone changing the size and for what reason.

You'd be surprised at what people do and why HW. One reason could be that one of the previous owners might have gotten a good deal on tyres and wheels secondhand when replacing the tyres at some point.

HW.....I am NOT saying for one minute that they are not as the manufacturer recommends......it was just one more thing to consider re fuel consumption.

And of course when you buy a preloved vehicle you don't always get all original.

-- Edited by Boroma577 on Wednesday 4th of January 2012 11:31:12 PM

Happywanderer · The Master

I am getting some good responses here and taking all into account. I will work on this over a few long trips and write a book on it (keep notes lol)

All posts much appreciated.

Boroma577 · Guru

Happywanderer wrote:
I will work on this over a few long trips and write a book on it (keep notes lol)

Good idea HW....let us know how you fare with it.

dorian · Guru

People may find Google's calculator and unit converter convenient:
http://www.google.com/search?q=10+km+per+litre+in+miles+per+imperial+gallon

traveling bob · Veteran Member

Back in mid 1990 I had toyota van like yours and from memory I got about 6 to 8 kls per litre, so I think you getting about average.

Bob

petengail · Guru

Happywanderer wrote:
Have finally worked out some figures on Myrtles fuel consumption.
Not sure if this is good or bad but seems to be ok.
This is as accurate as I'm able to get using my navman I travelled 106.6 ks on a full tank.
When I refilled it took 17.89 litres.
Going by my estimation I'm using (about) 16 litres per 100ks.
How does that sound to anyone out there with more knowledge than me?
easiest way I know of working out fuel consumption is by the motormouth fuel calculator... see attached
http://motormouth.com.au/myvehicle/consumptioncalculator.aspx

Clare46 · Senior Member

I get about 10-11L per 100 kms travelling at 90-95km per hr but that is in a much newer Hiace that Myrtle.

Happywanderer · The Master

Thanks dorian and pete.
I went into the calculator and the results are 16.78 litres per 100 kms or 5.96 kms per litre.

Beth54 · Guru

Happywanderer wrote:
Thanks dorian and pete.
I went into the calculator and the results are 16.78 litres per 100 kms or 5.96 kms per litre.

Marj, I didn't realize your calculation was per 100kms. Now that it's sunk in that it's 5.96kms per litre, that's pretty good as far as I'm aware.

Smokeydk · Guru

HW..may I suggest you go to a news-agent and get yourself a vehicle log book.....about $2.......each time you get fuel.....you write in milage...ltrs......costs...get in a habit in doing it......and you will have a record of fuel/klm etc..

-- Edited by Smokeydk on Thursday 5th of January 2012 12:15:36 PM

Dougwe · Chief one feather

Happywanderer wrote:
I wouldn't have thought the tyres would be too small would they boroma?

Would have no idea how much her total weight would be. She's equipped with wooden cupboards down both sides. One side carries the sink, stove, gas bottle on the outside and food.
The otherside carries the wardrobe, another cupboard with electrical stuff, and the fridge. Plus under the bed/seat carries fold up table and chairs.
Then all the other stuff, like portable cooker, water hoses etc. I suppose it all adds up.

Marj,

If you would like to know the GVM of Myrtle, load her up with everything you want in her and take her to your local public weigh bridge or if you know a company with one and drive her onto the weigh bridge, you will be given, in writing, the GVM weight. There is a small cost unless you know a company and you might get lucky and they will do it for you as a cheapy or better still nothing. Good luck. DOUG

Happywanderer · The Master

Been to my tyre man. He has pumped tyres up to 40. He said not wise to go up to 45 as when they get hot after driving a while they can go up another 10 which would put them up to 55. Better at 40 going up to 50 when hot he said.
He also said the tyres and wheels are the right size.

Joe · Senior Member

For a 30 year old box van that sort of consumption is OK. I'd be comfortable with it anyway.

Air in the tyres - check the construction of the tyres before you up them over the 36psi mark. If they are a light truck tyre (with an LT designation) then you will be fine to take it up to 40psi, but if it is a passenger rated tyre then I would be more cautious. Publish the tyre designations (the numbers written on the side of the tyre) here for advice if you need help there.

Boroma577 · Guru

Happywanderer wrote:
Been to my tyre man. He has pumped tyres up to 40. He said not wise to go up to 45 as when they get hot after driving a while they can go up another 10 which would put them up to 55. Better at 40 going up to 50 when hot he said.
He also said the tyres and wheels are the right size.

Excellent news HW....so now you know that your wheels/tyres size is not a contributing factor....least not whilst ever you run your tyres at the right pressure.

03_troopy · Guru

Slightly off topic, but for anyone with an android smartphone a very handy app is FuelLog. It can keep running totals and averages on refuels and can even handle partial fills and averages the result with the next full refuel. I used it to keep track of consumption and prices etc travelling to Alice Springs from Newcastle, and have a separate vehicle profile for normal day to day usage since coming home. I only use the free version which seems to do most of what I want. There are other similar apps around as well, and I'm sure there are plenty for the Iphone as well.

Happywanderer · The Master

I am starting to feel more comfortable now Joe. He did say the extra air won't make much difference to fuel economy so that would be interesting to work out.
They are light truck tyres 185/ something. Remember looking at it when he was putting the air in.
Maybe just best to fillup when its nearly empty each time and not worry too much about all the figures.

Happywanderer · The Master

I will get a vehicle log book next time I'm at a newsagents smokey.

My family are starting to call me by my brothers name jokingly now as he has written every purchase and mileage in notebook since he bought his 1st car in his teens. he is now 65. And he he has his head full with it all the time, every little detail.

gold dandelion · Senior Member

it appears you are getting around 6km to the litre. 348 KM to the tank. i reckon that is par for the course if you can get seven you are doing really well, I think if most people work their consumption out properly, towing a van they dont get any more. i have run into people who say they get 10 km to the litre. when you look at their rigs you just laugh to you self... especially when you see them filling up every time you do.
As with the tyres keep an eye on the middle treads if you over inflate you will wear them out before the edges, i would then let some air out. new tyres to early can buy you a lot of fuel.

ken thomas · Guru

Marj
Go to neils transport in Ogilvy ave as they have a public weighbridge
Ken