Never realized that by backing off of the rpms when working would increase fuel economy so much. Scenerio: D6r: when running wide open throttle (2100 rpm) I was burning about 7 to 8 gph (closer to 7). When I backed off to 1925 rpm fuel consumption went down to about 5 to 6 gph (closer to 6). But that is still a savings of over $3 per hr. Ten hr day that is a savings of $30 per day * 5 days=$150 per week * 4 weeks = 600 per month. It has not really decreased production either because the machine pulls down to 1900 rpm in WOT. It does decrease back up time, but by very little. I was wondering if anybody else does this?
I always try and keep my RPMs low and just about never backup at WOT. But your right all the hydrostatic iron I've ran normal runs best at WOT and uses a lot more fuel doing it.
I have always found that on most diesels, there is a point at about 3/4 throttle where torque is max. I do 90% of my work at this point with better economy than at WOT. Very seldom do I use WOT. It does not take very long working on a new machine to find the max torque RPM.
The last dozer I used was a rental Komatsu D32 Komstat. It was a great little machine, but with the hydrostatic drive, you had to keep to engine up higher than I like for a rental as it makes the hours tick over faster.
i have never thought of trying it with a dozer but it makes sense. when i run back hos i keep the rpms lower than wot in order to save fuel, good thought ill have to give it a try.:drinkup thats also a cool break down of cost and production
Pushkid, It took me a while to figure out the perfect rpm but on my 6R with the C9 engine the 1900 to 1925rpm range is just right, anything faster it doesnt help that much and anything below 1900 seems to be just too slow.