Maxximun Mileage

recently i have been monitoring my gas mileage closely, since i just put on an under drive pulley and wanted to see what kind of mileage gains i would get.

before i was getting 23 - 25 mixed city and highway. on highway normal revs are 3250 at 70 mph.

now after i ahev noticed mileage of 24.5 - 26 Mixed. this is around 2750 - 3250 rpms @ 70-75 mph.

anywho my question involve the rev range at which i am cruising.(this is all after the pulley is in) normal driving is around 65-70 mph 2750-3000 rpms. getting solid 25 mpg. a couple days last week i was driving out to coon rapids, and 610 is virtually empty so i was going faster roughly 80 @ 3250-3400 rpms. when i checked my mileage after that i noticed it was arounf 26.5mpg.

so my question is, is it possible that my car is more effecient at around 3000 rpms then at 2750 giving me more MPG, even though i am at higher revs?

hope this makes sense.

 

Not only does it make sense, but I notices the same thing.
22 city in my nsx 30 mpg at 75-80.
And the reason is exactly what you thought it was. Your engine is running more efficently (in a way. gear ratio and all), and it is also leaning out. No don't get confused with, "well I know it is the most efficent at 5k so I should do 110... bla bla bla" Wind resistance starts playing in around there too, and it is a cubical function, so it gets big fast.

 

so i believe my car rouhly gets peak torque at 4000 something. so would i see better mileage driving in 3rd gear at 4k vs drivin in OD at 3k?

 

so on the vacuum gauge it would be the larger vaccum you pull the harder the engine is working?

 

gotcha

 

i have a vaccume gauge somewhere...it helped ALOT when telling mileage it had good average and poor, cant find it though, i had it on my Z34...but on my soob, i cant get better then 22 mpg

 

My little "scan gauge" gadget tells me exactly to the tenths how much Gallons Per Hour and the Miles Per Gallon I'm using. Martin, if you would like to use it for a week for your testing, I'll gladly let you use it. But you have to have an OBD-2 port under your steering column. It only works for OBD-2 vehicles.

<u>Here's a small breakdown on what I've noticed on my 2000 Subaru Impreza 2.5 RS at cruise:</u>
I get ~2.2 GPH at 65 mph with 195/65-15 winter tires and 92 octane (non-oxy)
I get ~2.0 GPH at 65 mph with 195/65-15 winter tires and 87 octane
I get ~1.8 GPH at 65 mph with 205/50-16 summer tires and 87 octane

In general, wind resistance, throttle, inclines/declines, load, etc. all affect your fuel consumption. The more resistance put against your motor's rotation, the more fuel you're gonna use. The more air your motor injests, the more fuel you're gonna use.

 

in soobs...obd2 started in 1995, he should be just fine

 

i thought more backpressure at lower RPM makes more torque..because on my dirtbike, i have a supertrapp muffler, it said add disks for upper rpm power, and remove disks for quieter and more torque...is it different in cars? my dirtbike is a 4 stroke btw

 

i see, thanks for the info

 

after implementign some new driving techniques, i have noticed dramatically incresed mileage. this time @ about 1/2 tank of gas i ahve 195m. it came out to be like 28.3235MPG or somethign like that. this was mostly highway driving with some city.

this new technique includes:
slow accelrations
Cruising @ 1/32 - 1/16 throttle
stop over longer distance (coasting more)

Things to try next:
nuetral on downhills
slower turns
drafting

 

neat, i will look into getting a gauge

 

Yeah I get the best gas mileage in my truck at 74 MPH, at 75 it seems to go way down, I can't explain why, and I don't travel too much at lower speed than that, unless it's city only, but when I've traveled at 60-65 mph it didn't do as well.

My car gets 20, no matter what I do.... I can't figure it out.