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Fuel consumption
17 September 2018, 12:10,
Fuel consumption
On a motorway trip of 130 miles a few weeks ago with heavy traffic and stop/start motoring, in which for part of the journey it took 2 hours to cover 8 miles, our fuel consumption was 29 mpg this was with no luggage on board and just me and the OH.

This week we made a similar motorway trip but a total of 250 miles with 60 miles of that around the Manchester area where there are speed limits of 20 and 30 miles, total fuel used was 20.85 litres, this works out at 54.5 mpg, during which for most of the time the vehicle was loaded to the gunnels, as we were helping a relative move house.

Our second trip allowed us to accurately calculate fuel consumption and compare the effects of traffic congestion on our car.

Congestion almost doubled our fuel consumption ( maybe not your vehicle) but pleased be warned if you need to evacuate.
17 September 2018, 16:35,
RE: Fuel consumption
We have difficulty comparing our figures to your figures due to the Imperial gallon being 5 quarts and a U.S. gallon being only 4 quarts.

It makes your mileage figures look astronomically good when they are actually about the same as we get over here for the same basic model vehicle. You guys get a 20% head start on us.

The matter of congested fuel consumption is a matter of constant acceleration and braking. A vehicle sitting at idle will not consume more then one quart/liter per hour. That is with no load on the machine.

It is not the sitting at idle in the congestion that uses the most gas it is the start-stop activity.

Over here there is some increase in fuel use while sitting due to the almost universal use of automatic transmissions. With an automatic trans there is always a load on the engine even when dead stopped. That not only uses fuel it keeps the engine on the verge of overheating constantly.

Fuel use during acceleration is magnified with a tiny engine of less than 2L trying to gain speed repeatedly. They get great mileage flat out on the motorway but you are not always on the motorway doing the most efficient use.

My FIL found this out when he bought his first hybrid vehicle. He got fantastic mileage on the highway but no better than any other small under-powered vehicle in congestion and he never reached the manufacturers advertised mileage figures. I used to tease him by telling him they did the testing in Canada on the 5 quart gallon!

Back in the 1970s we had a national speed limit of 55mph imposed on us due to the Arab fuel embargo. It had been determined that 55 was the most efficient speed for an engine to operate, which was baloney from the start. your engine is best at an RPM range, which often does not match a specific speed.

During WW2 we had a nationwide speed limit of 35mph imposed as a fuel saving measure. I do not know if 35 is the most efficient speed for saving fuel but it gives new meaning to the question "Are we there yet?", and it sure does make you sit down and think "Do I really want to drive for two hours just to see that little red haired girl?"

Of course you folks had rationing and no fuel available for non critical use. That rationing continued after the war and influenced your selection of engines to this day.

We had rationing at 10 U.S. gallons per week per family, not due to a shortage but to ease up the pressure on the refineries cranking out product for the war effort. We were supplying us and you also.

I have always thought that too much consideration was given to fuel consumption in SHTF situations. My philosophy has always been to get where you are going and stay put. You do not need to go check on Aunt Martha three times a week, work your turn for the car pool, or run 20 miles to the supermarket.

You just need to get where you are going and sit there. If you do need a vehicle for a trip it is going to be a dangerous, hair raising experience you might wish you had not started rather than a simple run down the road to scavenge some plywood.
17 September 2018, 17:45,
RE: Fuel consumption
I still (somewhere) have the petrol coupons issued to my father during the suez crisis of 1956.
17 September 2018, 22:10,
RE: Fuel consumption
The plain fact that Pete points out .....excessive fuel consumption you would likely use up trying to bug out (to late) is tempered by MB's warning of the dangers involved trying to get (anywhere) and i agree entirely ....even more important is timing ....when to make your one chance only move in your bov to your bol ....if you leave it late you could well seal your fate (in a bad way) leave early your chances increase big time ....the rub is knowing when the time is right......most will bug in (especially if in a rural setting) you tend to feel safer plus all your preps are at hand ....and you know your area ....but this does not mean its safe...just because YOU think it is so......there are no guarantees what ever one decides ..there will be consequences ....hopefully positive ones
The ability to laugh at yourself while you learn is a great attribute.
17 September 2018, 23:51,
RE: Fuel consumption
If nothing else try to keep your fuel tank as full as possible at all times, NEVER let it drop down below half.
18 September 2018, 16:50,
RE: Fuel consumption
There is also the storage of fuel factor, which we talked about in another thread recently.

I am still trying to use up the tank full of fuel I purchased and filled the Jeep, back in March of 2016. I am down to 1/4 tank now. It is still starting and running like any good Jeep should, even on fuel pushing the year and a half mark.

That half tank of petrol in the vehicle will keep a gen-set going for several cycles to preserve the deep freezer. It would also be fuel for the roto-vator for next years' gardening, fuel the chain saw or weed trimmer. (You will need to keep those weeds down to deny their use as cover and to keep rats under control).

The half tank rule is a good one if you can keep the other family members from using it up and tossing you the keys and reminding you the tank is now empty.
18 September 2018, 16:57,
RE: Fuel consumption
BTW, I own an ancient Johnson outboard boat motor.

On the inside of the engine cover there are some specific engine requirements including the proper fuel mix necessary for the 2 stroke engine to operate.

The proper mix on the cover specifies that if 2 stroke oil is not available in remote areas of the world, standard engine oil can be substituted with no ill affects.

The average vehicle will have 20-30 liters petrol in a half tank and 5-6 liters of engine oil.

So view that parked vehicle with 1/2 tank of fuel as a two or three year supply of 2 cycle fuel and oil rather than an eyesore.

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