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Re: 602A Adventure

Posted: Tue Jun 12, 2018 3:12 pm
by Fernando BR
Guido , speedo shows almost same GPS speed with those tires , and very precise with maths

3000 rpm/4.9/0.806 = 759.60 rpm at wheel or x60 = 45 576 rph at wheel.
One wheel turn corresponds to (31" x 3.14 x 25.4) mm = 2,472.47 mm/wheel turn or 0.0024725 Km /wheel turn.
So 45.576 rph x 0.0024725 Km/ wheel turn = 112 Km/h
With no overdirve truck will be at 90 km/h at 3000 rpm , and will need near 3.700 rpm to the same 112 Km/h....Bad !!!!
On wolf with 5.2:1 axle you will need 33" tires and overdrive to have same 3000 rpm and 112 Km/h

Re: 602A Adventure

Posted: Wed Jun 13, 2018 4:09 am
by bram_r
Fernando BR wrote: ( i am going to change oil again at 3500 Km and after at each 7000 km )


Lots of oil changes, why so often? Is that what the manual specifies?

Fernando BR wrote:Guido , speedo shows almost same GPS speed with those tires , and very precise with maths

One wheel turn corresponds to (31" x 3.14 x 25.4) mm = 2,472.47 mm/wheel turn or 0.0024725 Km /wheel turn.


You'll be slightly wrong calculating the distance this way. Your tire may be 31", but the radius between center of the hub and ground is not 1/2 * 31", because of tire compression under load, thread depth etc.

If want to calculate this distance per rotation, mark the tire and the ground on a certain position and then move the vehicle forward until the tire mark is a the bottom position again, mark the ground here again. Then measure the distance between the markings on the ground. This is your distance per one tire rotation.
If you do multiple tire rotations, you're fault in measuring and marking will be reduced.

gr. Bram

Re: 602A Adventure

Posted: Wed Jun 13, 2018 4:55 am
by Fernando BR
Hi Bram , about oil changes , manual specifies only one at 1000 Km and then normal periodic changes . Its my decision to change at 500Km / 1000 km and 3500 to keep engine clean of steel particles (new long block) , not mandatory but each oil change i feel engine smooth . 7.000 km is my avarege anual use (3 trucks) , so one oil change a year.
You are absolutaly right, my rpm/speed calculation was only to give an idea , not precise , those figures 31" , 32" , 265x80x16 are commercial not precise. I think tire rack gives an idea of real size , but your method is the best for sure.