Fuel efficiency

[roryjohnson]

Hi everybody

I was hoping to get some feedback from all of you on the topic of fuel effiency.

Lately I've been riding around the city a lot on my 1980 R65, with a lot of stops and starts and quite hard acceleration.

I calculated my fuel consumption after the last fill, and it comes out around 29MPG or 8.1l/100km. I thought this was pretty high, and when I searched online and found that the average should be around 5l/100km.
However I'm not sure if this difference is that I'm doing pure city riding.

Does anybody have some of their own city figures for comparison?

Thanks a lot, greetings from Barcelona!
Rory

[georgesgiralt]

Hello !
Mine is an '82 so quite different.
I get 6~6.2 l/100 km in town and, effectively, around 5~6 l/100 out of town.
This is after a full cleaning and rebuild of the carbs... and a complete tune up.

[montmil]

 Lately I've been riding around the city a lot on my 1980 R65, with a lot of stops and starts and quite hard acceleration.  

With your riding description, you're probably getting the best you can from the R65. Same with four wheels -city driving just takes more fuel. Lots of automobile and pick-em-up trucks 'round here would love to get 29 mpg / city.

Both my R65s, 1981 and 1983, get a bit over 40 mpg which is combined city, county roads and a bit of higher speed highways.

Also, when riding in town, I usually stay a gear lower than you might think. The alternator does a poor job charging the battery at low revs and city work. The lower gear and slightly higher rpms keeps the battery happy and does impact fuel mileage a bit.

I'd much rather spend an extra pint of fuel than have to push the rascal. I've long since quit checking mileage. In town, reserve will get me to a station. On road trips, I just flight plan for 40 mpg.

[nhmaf]

I don't generally have much city driving to do, so I usually get between 19 - 21 km/l, though in very heavy, stop&go traffic where I couldn't get above 3rd gear I was down around 12-14 km/liter

[Barry]

You probably think this an unfair comparison between an R45 and R65 but I'm hauling exactly the same weight. The figures have been accurately recorded for almost 7 years.

My 7 year average is 65.61 MPH Imp. That's approx 54 MPG US. I improved on these long term averages by a series of careful carb settings and the most recent averages have been higher each year. I'm guessing I've plateaued out now. I see a big variation from summer to winter which is a reflection on typical journey length. As has been said short trips reduce fuel efficiency considerably. Average for this summer was 73.1 MPG Imp and for last winter 65 MPG Imp.

The key to good fuel efficiency is clean and accurately set up carbs. There are other things that can be of marginal help like semi synthetic or synthetic transimission oils, and properly set up wheel bearings. Carbs are the place to start though.

[roryjohnson]

Thanks a lot guys, extremely helpful as always!
I'm trying to drive more sedately and see if that improves things much
best
rory