2006 G35 Sedan Running at 2900 RPM at 70 MPH constant speed

[infinitig35H]

Could anyone explain why this happens? I have noticed this high rpm when the vechile is running on a flat road no ramps or slopes. I consulted the dealer but got a reply that for 70 mph the rpm is normal to be in the range of 2000 to 3000 rpm. I am not totally convinced since the other G35's (even 2004 version) seems to be running below or at 2500 rpm @ 70 mph.

Any good explanation?

[Poyzinous]

That sounds right to me. Is that in manual mode or auto? Or is it a Manual transmission?

[infinitig35H]

no its auto mode.

[tollboothwilley]

Stock diff is 3.3 in the 5AT and when I was running the stock differential I was at 2875 rpms in 5th gear going 80 MPH...

Unless you are in 4th gear, something is wrong.

[infinitig35H]

I am not that conversant with car engine. Could you please eloborate what "Stock diff is 3.3 in the 5AT " means? what RPM should we expect at 70 mph?

[Poyzinous]

at 70mph you should be at about 2700 rpms...However, if you're in manual mode, it'll be higher because the torque converter isn't in lock-up. Also, if the car isn't 100% warmed up, It will be revving a little higher than normal. 3.3 is the gear ratio for the differential, thats all it means.

[tollboothwilley]

Keep in mind the tachometer is not super accurate. Some people's cruise at 2900 rpms while others at the same are at 3200 on the tach. Using a OBDII reader is the best way to tell what your rpms are really at.

[telcoman]

Keep in mind the tachometer is not super accurate. Some people's cruise at 2900 rpms while others at the same are at 3200 on the tach. Using a OBDII reader is the best way to tell what your rpms are really at.

After reading this post yesterday I checked on my way to work today.With the speedometer registering 70 MPH my tach read 2500.However since my Garman Nuvi 265 WT also calculates my speed from the satelites, I plugged it in. It told me I was not doing 70 MPH but 67MPHWhen i increased my speed to 70 on the Garmin my speedometer in the G was about 73 and the tach was at 2650RPM

I do have a OBDll Actron but I don't feel like messing with it in the dark on my way to work. Its enough I have my Dunkin Donuts coffee mug to deal with.

Whenever I drove a G35 5speed auto loaner the RPMs were higher than my 6 speed manual.When I had a 2009 G37 7speed loaner the RPMs were lower

Telcoman

[srv2nv]

Checked mine out last night on the way to work. At 70+/- MPH I'm roughly at 2525-2550 RPM's.

03.5 G35 Sedan 5AT