Varying rpms

[barrysharp]

I'm curious to know just how one goes about varying the engine's rpm during the engine break-in period.

Most people agree that during engine break-in period the engine's rpm should be varied.

Under normal driving conditions (using auto vs. manual Geartronic) such as commuting at around 30-45 mph and highway driving at around 50-60 mph the engine's rpm will be operating in the 2000 rpm range.

Yes, during accelerating and decelerating the engine's rpm will climb or fall. However, the predominate rpm range will always be at or around 2000 for much of the road trip.

The 1500-2000 rpm range is selected by the automatic and gearing presumably because this is the range that the engine produces its max torque and quite possibly is operating close to its max efficiency.

If you agree with the above, then do you also see that the only way to control varying the engine's rpm for the above road trip examples is by using the Geartronic in manual mode?

[budrichard]

Except for red line RPM's, normal driving should vary the RPM's enough. The vehicle's initial RPM is 1500 and after a period slows to 1000 and depending on the idle conditions will be above 500. Acceleration shouldl get you about 3000 and the rest is for later. -Dick

[silverstar]

I was told the best for break-in is winding roads and city driving with out pushing it.

Having it on cruise control on the highway for long periods of time is not recommended during break-in period. The idea is to break-in the engines cylinder walls evenly as not to cause any ruts through out the RPM range but not exceeding the max RPM's specified by the manufacture (4,000 rpm) during the break-in time. You can go on the highway but it's good to alternate your rpm's through throttle control.

The geartronic can be a very good way of controlling the rpm's through the gear selection. On the highway, your gear should be staying the same most of time unless your slowing down and accelerating beyond the throw of the gear or if your going too low or too high in rpm's, then you'll need down-shift (rpm's too low) or up-shift or even slow down (rpm's too high). It can be a little annoying for the passenger having to endure a long highway passage with the driver varying (with in reason) the throttle.

I'm curious to know if anyone does it differently with their Volvo. I hope I've got right as I'm picking up my XC70 next month.

[barrysharp]

Dick:

I appreciate your reply http://xc70.com/iB_html/non-cgi/emoticons/smile.gif

What is nagging at me is that for both my 1986 Volvo 745 turbo diesel and my 2000 S80 T6 whenever I look at the Tach during a road trip once reaching a near constant speed the reading is always in the 2000 rpm range.

I don't have my XC70 yet to see if it acts in a similar way -- but I'm thinking it will.

This is a non-issue once beyond engine break-in period.

I'm certainly not overly anxious about this at all -- but simply wondering and have never ever concerned myself with this in the past for a new car.

People have always said -- don't run your engine at constant rpm for too long during engine break-in http://xc70.com/iB_html/non-cgi/emoticons/confused.gif  Well, if for normal driving the engine runs predominantly in the 2000 rpm range just how does one avoid this -- and maybe you don't as you have said.

[pico de luuks]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (barrysharp @ April 18 2003,19:24)</td></tr><tr><td id="QUOTE">People have always said -- don&#39;t run your engine at constant rpm for too long during engine break-in http://xc70.com/iB_html/non-cgi/emoticons/confused.gif Well, if for normal driving the engine runs predominantly in the 2000 rpm range just how does one avoid this -- and maybe you don&#39;t as you have said.[/QUOTE]<span id='postcolor'>
Use the geartronic in manual&#33; That gives you more control over the rpm http://xc70.com/iB_html/non-cgi/emoticons/wink.gif Be carefull to shift up in time http://xc70.com/iB_html/non-cgi/emoticons/sly.gif

http://xc70.com/iB_html/non-cgi/emoticons/pico.gif

[wiz]

Even in automatic it&#39;s just a question of taking your foot off the accelerator and then putting it back on. It doesn&#39;t have to be dramatic, you don&#39;t have to be constantly using the full range of 1-4K revs, just ensure that you don&#39;t stay at the same revs on the tach all the time. Not a big deal.

After it&#39;s run in, do the opposite, on a regular basis, like once every couple of weeks or so, redline the engine so that you don&#39;t get gunk collecting in the cylinders. Just put it into 1st gear and drive it until you see the tacho registering your redline. The engine behaves pretty interestingly up there... http://xc70.com/iB_html/non-cgi/emoticons/biggrin.gif

[mrb]

I agree with Wiz--not being mechanical minded or having any inclination to knowing how cars work--my break-in with all my other cars have been by now &quot;gunning&quot; it and by letting-up on the gas peddle to vary rpm&#39;s.

[Willy]

Hello,
Since I ordered a new car and I will probably have to make a holiday trip while it is still quite new, I have done some research on breaking-in a modern car.
Just as a lot of members already mentioned one should be gentle with the car, not only the engine though. It seems that brakes for example also need some time to breake-in (right&#33http://xc70.com/iB_html/non-cgi/emoticons/wink.gif.
Furhtermore, the engine will not be happy when subjected to very heavy loads, certainly not at low revs.
It seems that modern angines and oils are so good that a new engine, when up and running, will not breake-in at all. This happens mainly when the oiling is at a treshold (when started and stopped). Also small particles worn off will atribute. This means that the first oil should not be removed too soon and that when making long trips, these distances should not be regarded as contributing to the break-in of the car (no harm done however).
Greetings,
Willy

[wiz]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Willy @ April 20 2003,21:02)</td></tr><tr><td id="QUOTE">Also small particles worn off will atribute. This means that the first oil should not be removed too soon[/QUOTE]<span id='postcolor'>
Agreed, Willy. And Volvo wants the first oil change at 7500mi/12000km and you should follow their advice.