simple Q:

what is the difference in gas mileage between different gear ratios?

4.10
3.73
3.55

on the same truck, same stretch of highway etc.

also, " IN GENERAL" does an automatic tranny get better gas mileage than a Manual?

thanks

Trout74

 

I've got 3:55s and get 18.5 last refill , with mixed [50-50] hwy- in town , and doing more to get better, but besides the g. ratio the next best is how you drive, try to use the throdle lightly and the brakes even less.

 

Thats a tuff question to answer since everyone drives differently and tire size matters too....maybe a 2 mpg difference between a 4.10 and a 3.55

 

I've got 3.55's, and depending on how much smoke I want to see, and believe me, at times it is alot I average 20 to 21 mpg

 

3.55 and 4.10


Here is my experience with both I get 16-18 mpg in town with the 3.55 on the dodge ram you see in my sig, or is it 3.54 i dunno, at 70 mph at 2000 rpms i get about 20-21 mpg

I used to have a 1993 F 250 4.10 five speed 4x4 regular cab long box with 235 ten ply tires and straight pipe and K&N as only mods, I would get 60 mph at 2000 rpms, in town mileage was at 15-16 at best, and highway at 70 was almost at 2300 rpms so that was about 14 at 70, and at 60 it get about 18 mpg at best....

My dad with 3.73 gears in a chevy 3/4 ton gasser extended cab long bed 4x4, only mods are a K&N airfilter and aftermarket shocks, with a 350 with about 2000 lbs.in the bed gets about 10-12i n the city, and in the highway at 70 gets about 16-17 at best..

Hope this helps

 

Hi,
I drive very easy 2100 rpm max or about 60. I get a few "birds" but I drive in the right lane and pull over and let a line behind me go by occasionally. I watch the mpg like a hawk. I get consistant 20+ mpg. Also I have noted that 80 deg F seems to be a good temp even with the air on. Infact it seems a bit better with the air on and windows closed. At 90+ it is harder to get the 20 but still possible. At 45-50 deg F 20 is the very upper limit. Below 40 deg F to about 20 F usually cost 1-2 mpg. Below 0 deg F and 15 is about tops on the highway on a good day. It's really hard to get the motor over 120 to 130 at this temp.

I have 4.10 gears and 5 spd and don't hot rod much. If you tromp on it and wind it up to 2600 a few times forget gas mileage and don't complain. haha

Probably the best towing I ever got was pulling a big dirt machine about 8-9k plus trailer on flat land and little wind and about 80 deg F. Mostly at night. We got 18 for over 1000 miles. We drove right at 2000 rpm about 58 mph where ever possible. My buddy's gasser Ford got 6-7 pulling the same load.

All hand calculated and fill it up to the neck wait for the foam to settle.

Last night as I was filling up a Ford guy pulled up onthe other side. I asked him what he was getting for mpg. He was happy as could be getting 16-17 empty. I think it was a 7.3 a bit older f-350 crew and 5spd? and 4.10. Popped his bubble when I said I just got 20.5 no load.

 

I've got 3.55 gear and between 55-65 MPH in most places I will see between 16-18 MPG (Current average MPG is 17.47) on most normal driving without a trailer or load. The best even seen in my truck is 22.92 MPG and the worse is 15.59 MPG.

The biggest factor is keeping the skinny pedal out of the carpet...

Biuld your speed slow and easy... And keep your speed down.

 

thanks!

what about the tranny, is the manual or automatic better in general for gas mileage.


Trout74

 

Manual

More control over everything, PS i forgot to mention that dads ride has 235 tires too... anyways the auto will shift when it needs it, the manual just gives me more piece of mind for gear selection, and for better mileage, i cannot speak out of experience tho..

PS Trout, welcome to DTR!!! put ur ride in the sig so we can better assist you

Tx

 

tried to change my Sig.

I have a chevy 1500 Z71 now, I want to get a new dodge, and will this fall.

Trying to decide what gears I want and wether to get a Manual or Automatic.

Im very excited to own a Cummins, today is my Birthday (31) tried to convince my wife that its a good day to buy new truck, she just laughed and said enjoy your new shorts and shirt I got you, and ill take you out for dinner!

Doh!!!

Trout

 

In general, it has been my experience that a rig with an auto will usually get a couple of miles per gallon less than a similar rig with stick.

With our trucks, though, if there is a difference, it seems to be very small, perhaps a fraction of a MPG. I suppose that could be because the auto has a higher overdrive than the manual...

Like someone else noted, since everyone drives a little different, it's hard to make an exact comparison. In my truck, speed makes a huge difference...

 

I have 4.10's in my '99 w/five speed. I was getting 21.5 - 23, mix of hwy and street. I drive fairly easy (less than 8PSI accel) and drive no faster than 60 (2150 rpm). My milage has dropped and I have been around 19.5 to 20.5. I feel I have either and injector spray issue or a VP . I have 3.55 on the shop floor. I personally don't like running the engine above 2000 constantly. Thats fine for accel. os passing but I would like to keep it down. They would be in the truck but UPS damaged/lost the bearings and shims. Now I have to buy th install kit again.

The 2000 we only had for about two fills but it got about 22 (mostly hwy). With the automatics there will be varicance depending on the mods. Do to the poor quality converters it actually helps milage if you accel. a little faster and get it locked up. If you accel to lightly you will find a point of equliberium. It just slips with little speed change.

Personally I like manuals. Mostly because if it breaks I can fix it. I don't have the experiance or equipment to rebiuld an auto. The manuals is pretty simple.

Randy

P.S. All calculation are by hand. I track every tank of fuel in a book I got from Office Max.