Fuel mileage.

[weldingrod]

I know my carb needs changing because it is leaking a little gas but then I see others getting 15-18 mpg. Don't know if my calculations are off (I hope not) but I come up with around 23 mpg. Not sure if I am calculating correctly.

 

[datzenmike]

 Simple the Imperial gallon is 4.546 liters and the US gallon is 3.785 liters. So a Canadian gallon will be taking you farther than a US one.

 

23 MPG (Canadian) X 0.354 = 8.142 liters per 100 km X 2.352 = 19.149 MPG (US)

[Thomas Perkins]

My 85 4x4 5- speed ,2.4 gets 18.5 mpg.Been that way for 28 years,It gets the same with the Weber and the old stock Carb.This is what it is suppose to get.I check mine every time I fill up.I do burn 93 octane.Also I don't speed.They have radar's around here.This is the average..I had used the regular NGK spark plugs and now use the NGK Iriduim and their is no difference in the gas mileage.Now that it is getting hot,I will start using the A.C.Just filled up and paid 4.79 a gallon,58.75 to fill it up with 12.243 gallons.The most I ever paid,I usually fill up with a little over 12 gallons,it holds 15.7 gallons. .https://www.fueleconomy.gov/feg/bymodel/1985_Nissan_Truck.shtml

Edited June 7, 2022 by Thomas Perkins

[720_Jeff]

Over 5 years, some 2300 gallons, I was averaging 23.3MPG.  Best was 30MPG.  Don't recall the specifics of that tank, do recall another where I got 28, it was mostly flat, all highway with very few stops.

 

Fully, has some data for ya

https://www.fuelly.com/car/nissan/720

 

This was my truck, before I sold it

https://www.fuelly.com/car/nissan/720/1986/jjatkin/777043

 

Edited June 7, 2022 by 720_Jeff

[powderfinger]

I always got in the low to mid 20s on my 2wd 720 with a weber carb, more times than not it was in the mid 20s. Most of the miles were around 60-65mph. My 4x4 seems to be averaging a little less than 20, too early to tell for sure yet as I am still messing with it.

Edited June 9, 2022 by powderfinger

[pdp8]

I'm surprised at the rather abysmal mileage the 720s seem to get.  Looking on the EPA website suggests about 20 for the 4x4and more like 27 for the 2wd and I was wondering why the vast difference, but to see people report it here seems to confirm those numbers as plausible.

My Mitsubishi pickup got a reliable 29MPG and the Mazda PU owners of similar age report 30-40+, so what did Datsun do that was so different I wonder?

 

I love the look of the 720, but if I'm going to get sub-20 MPG, I'll have to pass.

Edited August 28, 2022 by pdp8

[Stoffregen Motorsports]

What Datsun/Nissan did is more of what they didn't do. They used ancient engine technology. Massive rings on heavy pistons. Single overhead cam with two valves per cylinder. Dual row timing chain, etc. Nothing light weight. Other import cars and trucks of the period had multi valve cylinder heads and low tension rings on pistons with a short pin height, single row timing chain and lighter (weaker) components altogether.

 

Toyota's 22RE suffered from the same problems. But, there is an upside to these heavy engines - they last forever and can be rebuilt in the middle of a dust storm using a butter knife, a hammer and some sand paper.

 

The KA24E ushered in a whole new way of engine building for Nissan trucks. It wasn't a major improvement, but it was a start in the right direction. EFI helped a bit too.

[datzenmike]

... and vehicle weight.

[Thomas Perkins]

wow

Edited August 29, 2022 by Thomas Perkins

[banzai510(hainz)]

i get about 20 with my 521.

everybody thing these things get great gas milage. Its not true with the older 4 cylinders.

It only looks good as the old V8s got 11 miles to the gal

[datzenmike]

I got 30MPH strictly highway driving in my 620. That's 24.9 something miles on a US gallon. At home around town probably way under 20.