Andyinchville1
Veteran Member
Hi All,
Here are some updates ...
Over the years , I updated the car as parts wore out / needed to be replaced (see signature) .
In the past (pre mod / stock ) my MPG's typically hovered in the 47 to 49 MPG range based on the driving I did.
After many of the mods (in signature) I routinely got into the low 50 mpg range doing the driving I typically do ( the max before my "peak torque" experiment was about 51.4 MPG and that only happened once before ( I think I was just driving slow without regard to peak torque)
Whereas before I only hoped to break 50 MPG , I later got "spoiled" and expected 50 MPG tanks and felt bad if it went below that.
Anyways, for the last 7 tanks , by driving at roughly 1950 RPM (near peak torque) here were my results ...
52.07
54.7 - AC sometimes off
56.85 - AC sometimes off
54.5 - AC sometimes off
52.83
51.56
52.68
These tanks were regrettably in just my regular driving and not on a set / fixed course (I used to do a 500 mile regular courier run but unfortunately (fortunately?) I don't do that loop anymore .... that regular run would have been good to see actual changes resulting for mods or driving style since it was consistent .
Seemingly, just driving at peak torque has helped my fuel economy BUT I wonder if the larger 205 75 tires contributed to this ?
Let me explain ....
I read somewhere that operating at peak torque is best for fuel economy BUT the engine has to be loaded also (loaded as in terms of gearing load).... BUT within reason ....
i.e. operating at peak torque in 1st gear is not much load and will not net out good MPG because not alot of load on the engine BUT operating in 5th gear at highway speeds would get good MPG at peak torque (assuming to aren't trying to climb a 45 degree slope!.
I guess its the whole "in moderation" thing as far as load at peak torque for best MPG?
I think maybe my switching to a bigger tire helped load the engine (by better / higher) gearing to eek out the better MPG figures ? (note I went from LRR ecopias to just bigger (not LRR) Hankooks so it most likely was NOT a more efficient tire design causing the MPG increase but just the diameter / gearing ?).
FWIW tho (in thinking about it) I used to try to keep speeds around 60-62 MPH when using the smaller tires which would be beyond peak torque (currently 1900 RPM is about 59 MPH).
Maybe I'll experiment with faster speeds but it is hard for me to do unless I run daytime more (most of my driving is at night on deer filled roads so I keep speeds lower (lower than posted even) .... I "hot rodded" it last night at the speed limit just to see more MPG figures driving at (or very near) peak torque....
Anyways, my preliminary findings are ..... get bigger tires and drive at peak torque ;-)
Here are some updates ...
Over the years , I updated the car as parts wore out / needed to be replaced (see signature) .
In the past (pre mod / stock ) my MPG's typically hovered in the 47 to 49 MPG range based on the driving I did.
After many of the mods (in signature) I routinely got into the low 50 mpg range doing the driving I typically do ( the max before my "peak torque" experiment was about 51.4 MPG and that only happened once before ( I think I was just driving slow without regard to peak torque)
Whereas before I only hoped to break 50 MPG , I later got "spoiled" and expected 50 MPG tanks and felt bad if it went below that.
Anyways, for the last 7 tanks , by driving at roughly 1950 RPM (near peak torque) here were my results ...
52.07
54.7 - AC sometimes off
56.85 - AC sometimes off
54.5 - AC sometimes off
52.83
51.56
52.68
These tanks were regrettably in just my regular driving and not on a set / fixed course (I used to do a 500 mile regular courier run but unfortunately (fortunately?) I don't do that loop anymore .... that regular run would have been good to see actual changes resulting for mods or driving style since it was consistent .
Seemingly, just driving at peak torque has helped my fuel economy BUT I wonder if the larger 205 75 tires contributed to this ?
Let me explain ....
I read somewhere that operating at peak torque is best for fuel economy BUT the engine has to be loaded also (loaded as in terms of gearing load).... BUT within reason ....
i.e. operating at peak torque in 1st gear is not much load and will not net out good MPG because not alot of load on the engine BUT operating in 5th gear at highway speeds would get good MPG at peak torque (assuming to aren't trying to climb a 45 degree slope!.
I guess its the whole "in moderation" thing as far as load at peak torque for best MPG?
I think maybe my switching to a bigger tire helped load the engine (by better / higher) gearing to eek out the better MPG figures ? (note I went from LRR ecopias to just bigger (not LRR) Hankooks so it most likely was NOT a more efficient tire design causing the MPG increase but just the diameter / gearing ?).
FWIW tho (in thinking about it) I used to try to keep speeds around 60-62 MPH when using the smaller tires which would be beyond peak torque (currently 1900 RPM is about 59 MPH).
Maybe I'll experiment with faster speeds but it is hard for me to do unless I run daytime more (most of my driving is at night on deer filled roads so I keep speeds lower (lower than posted even) .... I "hot rodded" it last night at the speed limit just to see more MPG figures driving at (or very near) peak torque....
Anyways, my preliminary findings are ..... get bigger tires and drive at peak torque ;-)
