RPM Question
#1
#2
not mine, at 75MPH I'm at 3000. RPM's doesn't effect gas mileage at all, you can drop to 4th gear and watch the instant mileage and it shows the same.
The reason for 3K @ 75mph is that it puts you more in the power band instead of choking the engine at 2100, and a lower RPM will actually lower MPG.
The reason for 3K @ 75mph is that it puts you more in the power band instead of choking the engine at 2100, and a lower RPM will actually lower MPG.
#3
Originally Posted by kring
not mine, at 75MPH I'm at 3000. RPM's doesn't effect gas mileage at all, you can drop to 4th gear and watch the instant mileage and it shows the same.
The reason for 3K @ 75mph is that it puts you more in the power band instead of choking the engine at 2100, and a lower RPM will actually lower MPG.
The reason for 3K @ 75mph is that it puts you more in the power band instead of choking the engine at 2100, and a lower RPM will actually lower MPG.
If not, why did car makers even bother with overdrive in the first place ??
If that were the case,we can all drive in say 3rd all day (MT models can go upto about 90 mph in 3rd) and get the same mileage as now!!
#4
I think this is one of the biggest drawbacks with the G35 setup. It's a great car, but the engine RPM at highway speeds is too high. Most of the other vehicles in this class get better mileage in part because of better overdrive ratios in the transmission. A lower RPM on the highway will almost always net you better gas mileage- 2100 RPMs will not put the engine under a lot of load under normal driving conditions. I have a 2005 3.5 SE Altima (auto) that runs at 2100 RPM's at 70 MPH/ 2400 at 80 MPH and with mxed driving, will get 26- 27 MPG. On a recent trip to Texas with all HWY driving I got 33.5 MPG (checked this manually- the computer is off by 1-2 MPG). It's hard to compare different cars but the G will not get close to numbers like this if the overdrive gearing isn't adjusted. The IS 350 has the same amount of power as the G ( with a minimum advantage in torque), has similar weight, but has better MPG- one of the main differences in the two cars is RPM's at highway speed.
#5
I went to Boston this weekend in my X and that was a 220 mile drive 1 way. Doing aobut 80-100 mph, my rpm was around 3700-4200. Even inthe city on local HWY i notice the rpm runs alittle high but i thought it was due to the short gear ratio. But goin 80-100mph it should be lower cuz it in a higher gear. Don't know if this is normal or not. Also HIGH RPM=LOW GAS MILEAGE. Example: Try stompin on your car from red light to red light, and you see how much gas you lose.
#7
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#8
Originally Posted by sjharris
thanks everyone. oh well, i guess i have to live with poor gas milage.
Mine shows an indicated 3K rpms @ 72 mph.
I assume mpg will go up slightly with more miles on the engine.
#9
Originally Posted by meng702
Also HIGH RPM=LOW GAS MILEAGE. Example: Try stompin on your car from red light to red light, and you see how much gas you lose.
high rpms with slight throttle can still yield good mileage with the engine always in or near the peak powerband. OHC engines are designed to run at higher rpms
Last edited by CarNutz; 03-13-2007 at 02:13 PM.
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#13
Originally Posted by acidrane
actually, to me, the rpms seems fine. in my old car at 80mph the rpm would be around the 3200 range. so i guess you can say im use to it.
#14
#15
Originally Posted by CarNutz
Not quite.. high rpms with wide open throttle means bad mileage.
high rpms with slight throttle can still yield good mileage with the engine always in or near the peak powerband. OHC engines are designed to run at higher rpms
high rpms with slight throttle can still yield good mileage with the engine always in or near the peak powerband. OHC engines are designed to run at higher rpms