Is it possible?
#1
Join Date: May 2006
Location: North Plains, Oregon
Posts: 1,497
Received 0 Likes
on
0 Posts
Is it possible?
Here is the question I would like help with. Will synthetic oil allow a diesel engine to run a lower rpm’s at a gives speed in a Dodge 2500 do to its use?
Example engine is a new 2006 CTD engine, auto that use to run at 2000 rpm’s @ 70 MPH and had done so for 10,000 miles of it being driven. Now with the use of off the shelf 5w40 synthetic it now runs between 1900-1925 rpm’s @ 70 MPH. The only thing that has been done to the engine prior to this was that it the oil changed 20 minutes before it was noticed that the rpm’ had dropped between 75 and 100 rpm’s @ 70 mph. Nothing else was done to the engine or drive train to change or alter it in any way just the oil change.
So was it because of the use of the new synthetic oil that allowed it to run at the lower rpm’s or some thing else, unexplainable, BS or is it [sm=ts.gif]
[sm=thanx.gif] for any help with this question and have a very Merry Christmas,
Charles
Example engine is a new 2006 CTD engine, auto that use to run at 2000 rpm’s @ 70 MPH and had done so for 10,000 miles of it being driven. Now with the use of off the shelf 5w40 synthetic it now runs between 1900-1925 rpm’s @ 70 MPH. The only thing that has been done to the engine prior to this was that it the oil changed 20 minutes before it was noticed that the rpm’ had dropped between 75 and 100 rpm’s @ 70 mph. Nothing else was done to the engine or drive train to change or alter it in any way just the oil change.
So was it because of the use of the new synthetic oil that allowed it to run at the lower rpm’s or some thing else, unexplainable, BS or is it [sm=ts.gif]
[sm=thanx.gif] for any help with this question and have a very Merry Christmas,
Charles
#2
RE: Is it possible?
I am not an expert by any means but I noticed the same thing. I have an 06 CTD with the 48RE trans and 3.73 gears. After I switiced to the Valvoline 5w-40 I noticed my RPM's dropped to 1925-1950 at 70 MPH too. I don't know if it is the difference in viscosity between the 5w-40 and 15w-40 or the difference between dino oil andsynthetic.
#5
RE: Is it possible?
Looking at race cars, they run a windage tray to keep oil from slinging up onto the crank while its spinning which would slow it down. The synthetic being thinner and easier to sling off would in turn put less "grip" on the crank allowing it to turn easier making for easier rpm's? Im no rocket scientist and could be completely wrong (not the first time LOL) but it sounds feesable.
#6
RE: Is it possible?
I think that there is some CTD voo doo going on here. Highway speed is a fuction of engine RPMs with constants of tire diameter, trans overdrive ratio, and rear gear ratio. The only loss is through the converter, but even in this situation, the converter is "locked" at high speed cruising.If the engine RPMs drop, then the speed of the vehicle MUST drop.
#7
Trending Topics
#8
Join Date: May 2006
Location: North Plains, Oregon
Posts: 1,497
Received 0 Likes
on
0 Posts
RE: Is it possible?
ORIGINAL: NickBeek
I'm not gonna call anyone a name..... but I can not imagine any way engine oil could effect fianl drive ratio.
I'm not gonna call anyone a name..... but I can not imagine any way engine oil could effect fianl drive ratio.
#9
RE: Is it possible?
I have an 06 CTD with the 48RE trans and 3.73 gears. After I switiced to the Valvoline 5w-40 I noticed my RPM's dropped to 1925-1950 at 70 MPH too.