Yes, ethanol is really a contaminant in gasoline. It has less energy than gasoline, so it cuts back on mileage. Not only that, but ethanol can deteriorate
the rubber in the gas lines and the seals in the fuel pump, so they have to add yet another substance to combat that.

I may try premium fuel, but I think even premium contains ethanol now, and premium fuel is 20 cents per litre (80 cents per gallon!) more expensive
than regular, so the savings in gas mileage are paid back to the oil companies in cost. Seems like the oil companies always win, doesn't it :-(

 

First off I never run my tank empty ever,,, never gets below 1/4 as with fuel pump being cooled by the fuel I like to keep it from getting to warm. Also i let my truck run for 10 mins morning and noon and after work to warm up and that uses a fair amount of fuel. . I keep mine turned up and change sparkplugs every 50k THen at least once a month I am on highway for a 800 km trip to help keep carbon buildup. As for premium gas I have tried it and lucky if I got 1/2 mpg better not worth it thats for sure.. Another thing, how aggressive are your tires? Seems like the more aggressive the tire the mpg goes down some, Are you running the stock 275/60/20 tires? And is that the right size that should be on it as you can get 2 different sized tires from factory,, 20 in and also 17 in tires, Like if it came with 17 in tires and someone put th 20 in on the speedometer will read wrong, as it will show less than you are going by 10 or more kph, Check the sticker on drivers side door to see what it came with

also 16L per 100 works out to 17.665 mpg and 20lL is 14.124 mpg

 

Thanks for the info re. premium. Yes, I do have 20 inch tires, and the door sticker says 275x65x20, so I am guessing that the speedo and odo are accurate.
However, that is very interesting and you are very clever to have thought about it, as it never would have occurred to me if the previous owner had upped
the wheel size from 17 to 20.

I agree that 16 L per 100 km is almost 18 mpg (Imperial, 15 mpg US) ... however, you said that you get 300 - 400 km on a 126 litre tank.
126 divided by 4 = 31 L per 100 km. If, of course, you fill up at 1/2 a tank, then yes, this is "only" 16 L per 100 km.

One thing I forgot to mention ... if I keep my dash display on "instantaneous fuel usage," it shows that even under the mildest acceleration from a stop,
the consumption pins the scale at over 40 L per 100 km! When cruising at highway speeds, it tends to show anywhere from about 14 to 18 L per 100 km.
Cruising the city, keeping up with traffic flow, it varies anywhere from 15 to 30 L per 100 km, and the Distance to Empty goes down at an alarming rate,
with km remaining usually decreasing faster than km travelled.

Of course, we can also debate the accuracy of this display (it is the old-style, small, in the middle of the dash, and not the newer large-screen display).

As always, thanks for your input.
Sam

 

Thanks for this comment. I was already suspicious of my sagging parking brake line and this comment also reminded me that I had noticed the light on (red P) after a service appointment and took it back to the shop
and they got the light to go off freeing the line a few months ago. I just tapped it back in place and the line tightened appropriately.
I might have to work on or replace hardware more but so happy to have the problem narrowed. Ive been getting about 9 mpg combined lol