tharoka

Any one can explain the reason of not to drive at one constant speed for a long time, either fast or slow, during the running in?

What can be happen if this hasnīt be respected?

What is understood as "long time"?

I really do need some advice.

Thanks

[Edited by tharoka - 11/14/2003 8:32:22 AM]

Andy McCord

i suppose that if you run it in at a constant speed the loads are very small, where as if you are up & down the rev range the loads are significantly higher & varied, which is what you want to avoid a tight engine

tharoka

...so it does not damage the engine (in any sense), neverteless itīs recomendable to do a "faster" running in. Iīm 2.100 Km at the moment and still havenīt reach 4.000 revs, an Iīll keep this way 500 km more, at least. Then Iīll will increase 500 rpm at reason of 500 km.

Is correct what I have done and what Iīm intended to do?

Here, in the Spanish Impreza Owners Manual, does not exist any servicing request untill 15.000 km. Iīm scared of it wouldnīt be to long period. I will like to change the oil and filter now. What is the best I can do? Here are different points of view, from a semy sintetic (due to the viscosity during the running) to a hi-viscosity fully sintetic as RS 10-60 (now called TWS...)

Iīm quite worried with this stuff, ...

LB4

I believe that there is an oil change required after the first 1000 miles, and then 10,000, at which time you can change to full synthetic.
Your running in procedure seems fine to me, and i wouldn't be too concerned with constant speed thing, unless you are driving for miles and miles on end at constant speeds it shouldn't be an issue.
I think the consequences are that its possible the bores can "glaze" from constant speed running, which is not desirable especially during the running in period.

Gary

tharoka

Confirmed too that, at least in spain, the fist service is at 15000 km.

Anyway as said before, Iīll change my oil and filter soon, next week surely.

After speacking with some engineers about relationated matters (Oil questions) I took advantage of and speack about the running in. Told me that there is a buch of mithology around it, and not to be aware, so I dont .

Thanks for the answers m8s!

ST AYE

I agree with LB4
I believe that the reason constant speed for running in is not recommended. Is that by varying engine loads, you are varying the force pressing the piston rings against the cylinder wall.
Under gentle cruise conditions the ring pressure would be low and constant.