everyone knows the 300's have awsome bottom end power. infact i take all of my 90 degree turns in 3rd gear, and it just chugs alone with out a problem. i know most engines can not drop down to 900 RPM or so during regular driving. so my question is is this harmful to my engine? i get some vibration when the RPMs drop that low (not alot) but the engine dosent seem at all fased by this. the only thing i can think of is it may not get enough lubercation at these low RPMs, or the slight vibration could loosen something up?. any one have a more informed opinion??

 

You are right about low oil pressure at low revs being an issue, especially if you are into the throttle a bit, lugging it and bringing cylinder pressures and therefore bearing pressures up.

Also, the gear box would rather spin a little faster under load as well.

Shift it down....

You can always skip gears on the way up and use the low end to accelerate at an even slower rate than usual if you like to show off the low end grunt...

900 in 3rd is a kiss away from a stall, imo.

 

If you run it at least 1500 rpm you will prevent lugging. Best is 2000 rpm because then it's ready to move out.

 

ya 900 is alittle to low if your trying to accelerate. but 1500 should be no problem, it wont have the most responce to throttle inputs because your below peak torque but it shouldn't be a problem

 

Yeah, try and avoid running below about 1,200 RPM, except in low gear/reverse.

 

Low RPM lugging is the worst thing you can do to your engine. The torque required to accelerate at low rpm's is much greater than if you went down a gear. This is hard on the bearings, as evidenced by the vibrations you are getting. Your engine will run much longer if you keep the rpm's up enough to prevent lugging.

 

I like to run the engine between 1500 and 2500. If I'm going up a grade I'll down shift @ 1500. I tend to bring it up to 2500 when going through the gears. 3.55 axle.
Save your engine, as stated by others lugging is hard on the engine.
regards
rikard

 

Over revving IS the WORST thing you can do to a motor!! As long as the oil pressure
is good and you are not towing or heavily loaded that will be fine to bring the motor down to now if you said 600 rpm that is a different story!!http://www3.telus.net/cbradley/Engin...fications.html

 

I noticed that after I put on my exhaust I can go 20 mph at 900 rpm. I was impressed! Love these motors.

 

I agree that over-reving is bad for the engine, especially for the 4.9L six, but most 4,9'ers are more prone to lug it down to low RPM's since it has so much torque, than over-rev the engine. For the majority of 4.9'ers lugging the engine at low RPM's is far for more damaging to the engine than over-reving. I would stake my engineering degree on it!

 

Depends on what is meant by "over revving." I would rather run my engine to 3800 rpm than lug it. But it's not likely that someone will over rev their 300 merely by avoiding running at low rpms.

 

As long as it's not bucking, shuddering, etc., at low speed under light to moderate throttle it isn't getting hurt. I routinely make a 90 degree right turn in third gear (3.08 rear and stock tires) at 10 mph with rpm dropping below 1000 with no problem. In town traffic I routinely upshift at 1500 rpm...again no problem. Driving on a 30 mph street in fourth at 1000 rpm...no problem. If traffic conditions dictate accelerating quickly using more than light to moderate throttle or one has a moderate to heavy load on or in tow by all means run it a little faster. Otherwise, don't worry about it.