I just purchased an 06 Ram, V6 6 speed manual. AllPar describes the engine as getting better fuel economy at higher RPMs. Does they mean I need to hold gears to higher RPMs before shifting? At 70 mph in 6th, the enging turns 2200 RPMs. Logic would hold this would produce the best MPG? At 800 miles total, I'm getting 16-17 mpg on the road and 14 city?

Thanks

Dan

 

NO all engines have a sweet spot where they run the best and get better MPG and Power.

If you running in to low of a RPM you are Lugging the motor down making it work harder useing more gas to push you truck along as in a head wind or hills trying to stay at 70 MPH with you'r foot though floor It is easyer on the motor to down shift to 5th And run a higher RPM you still sucking more gas you are running a higher RPM But It is easyer on the motor.

A lot of motor homes try to pull hills in high gear and end up haveing low oil pressure do to not enought RPM's and getting bad MPG they would of been better off going down one gear keeping the RPM's up going a little slower so you have the higher oil pressure so you dont blow the motor up remember at lowwer RPM's and floored you making lots of engine heat you need theOIL PRESSUREto keep it cool and Lubed up.

Normaly lowwer RPM's means useing Less Gas you are burnning BUT with 4999 LBS truck with our small 3.7 V6 sometimes Lowwer RPM's can hurts you wacth you'r RPM's and how much gas you are giving it to keep that speed up some times you are better off down shifting and holding the higher RPM's.

Where I live we have lots of high winds and rolling hills my truck can go the posted speed of 70 MPH in top gear 6th gear but I to the the floor trying to kep 2100 RPM's I am better off Down shifting back down to 5th and turnning 2500 RPM's I useing less gas and the motor is pulling easyer.

You other Option is what I going to one of these days I put a set of Lowwer rear end gears in that gives you more RPM's in high gear at the same speed but also give me some more tourqe out the truck which this 3.7 needs badly but you will lose some top end speed do it revs out sonner but once again I did not buy the truck to go Mach speeds. for instance if you truck did 130 top end you mite lose 5 to 10 miles MPH now you be top out at 125 to 120 MPH.

You be able to pull hills and head winds easyer with out down shifting as much but you mite even save gas MAY BE or mite use more most likley turn more RPM's more gas rule of thumb at least you truck will not struggle as much.

 

good info marv!! i have noticed that if you baby it the motor just lugs along, but now i know that im not necessarily saving gas. So if I give it a littlemore and find that "sweet spot" ill get better mileage right?

 

More or Less

I found 2200 to 2600 RPM'sIs about right for me for 3.7 sweet spot for power at cruise speed.
I shift around 2500 to 3000 RPM's Normaly unless getting up to HWY Speeds for a on ramp or stop then it's foot though the floor wind her up RPM's Are you freind thats where you make the horse power.

 

that sucks, i have an automatic so cruising at 50 the rpms sit around 1500. only when im cruising at like 70 do they get up to 2000.

 

I haven't had to put foot to the floor yet, but it is FLAT down here in north east Texas, behind the pine curtain. Most of the good ol' boys down here invested their live savings in the double cab, diesel one tons...and tow 30,000lbs of hay and trailer behind them.

My joke about the truck is that you have to down shift for speed bumps. I don't even use 6th gear until 65 mph. Nice on the interstate, but it takes almost to town before the engine is warm enough to use top gear.

Now, I do have the 68 sweptline with 3.90 suregrip...or the 62 Town Wagon with the granny low.

Howard

 

I am seeing the same thing as you.... sitting around 2000 on the hwy at 70. Have to take it off cruise control on long shallow inclines since the computer just hammers the rmps up to 4000 just to keep the mph at the set speed. This is my only regret in not purchasing the 4.7l. Got the 3.7l to save gas $$$$.