The Ford Barn

Lawrie · 08-18-2019, 12:33 AM

I have noticed these last few trips away in our 33 the fuel usage has gone up,
it used to be able to manage 18 ltrs per 100 klms easily,but has lately been all over 20L / 100.
So I did a bit of searching in my log books,
found that it changed in mid 2017, same time I had changed the cylinder heads,one of witch had a small crack, these were 75cc in the chamber. the ones I fitted were 82cc in the chamber,( only ones I had) nothing else had changed.
I had looked out for another set but to no avail, so I will repair the small crack and refit the 75cc ones.

Side note, the 33 just did the trip to the Mt Isa rodeo and back, great trip.around about 2000 miles .used no oil,
Lawrie

ford38v8 · 08-18-2019, 03:24 AM

There are other factors beyond your control that affect fuel economy: The formulation of fuel of late is done for political advantage rather than for the efficiency of the engine.

JWL · 08-18-2019, 04:01 AM

Getting less power from each liter of fuel, as happens when lowering the compression ratio, will lead to more fuel being necessary to accomplish the same work value. I am somewhat surprised there was not a noticeable increase in radiator coolant temperature also?

Karl · 08-19-2019, 04:53 AM

Quote:

Originally Posted by Lawrie

I have noticed these last few trips away in our 33 the fuel usage has gone up,
it used to be able to manage 18 ltrs per 100 klms easily,but has lately been all over 20L / 100.
So I did a bit of searching in my log books,
found that it changed in mid 2017, same time I had changed the cylinder heads,one of witch had a small crack, these were 75cc in the chamber. the ones I fitted were 82cc in the chamber,( only ones I had) nothing else had changed.
I had looked out for another set but to no avail, so I will repair the small crack and refit the 75cc ones.

Side note, the 33 just did the trip to the Mt Isa rodeo and back, great trip.around about 2000 miles .used no oil,
Lawrie

Lawrie - Those figures round town or on a trip? By my calculations 20l/100km is about 14mpg (imperial) . On my last trip over 1800 miles we averaged 20.5 mpg but round town its probably round 16mpg . -However I suspect you were towing your trailer ??

Karl

supereal · 08-19-2019, 10:22 AM

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Check your tire inflation. A few pounds low can have a pronounced effect on mileage. I run mine a few pounds higher than the book or sticker recommends. The octane level of the fuel is also a factor, particularly here in the US, where alcohol dilution is common.

08-18-2019, 12:33 AM	#1
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,215	fuel economy I have noticed these last few trips away in our 33 the fuel usage has gone up, it used to be able to manage 18 ltrs per 100 klms easily,but has lately been all over 20L / 100. So I did a bit of searching in my log books, found that it changed in mid 2017, same time I had changed the cylinder heads,one of witch had a small crack, these were 75cc in the chamber. the ones I fitted were 82cc in the chamber,( only ones I had) nothing else had changed. I had looked out for another set but to no avail, so I will repair the small crack and refit the 75cc ones. Side note, the 33 just did the trip to the Mt Isa rodeo and back, great trip.around about 2000 miles .used no oil, Lawrie

08-18-2019, 03:24 AM	#2
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,644	Re: fuel economy There are other factors beyond your control that affect fuel economy: The formulation of fuel of late is done for political advantage rather than for the efficiency of the engine. __________________ Alan

08-18-2019, 04:01 AM	#3
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: fuel economy Getting less power from each liter of fuel, as happens when lowering the compression ratio, will lead to more fuel being necessary to accomplish the same work value. I am somewhat surprised there was not a noticeable increase in radiator coolant temperature also?

08-19-2019, 10:22 AM	#5
supereal Senior Member Join Date: Jul 2014 Location: Iowa Posts: 1,634	Re: fuel economy Sponsored Links (Register now to hide all advertisements) Check your tire inflation. A few pounds low can have a pronounced effect on mileage. I run mine a few pounds higher than the book or sticker recommends. The octane level of the fuel is also a factor, particularly here in the US, where alcohol dilution is common.