- I currently own a 2009 mazdaspeed3, 6 spd manual, 2.3 turbo. I heard from multiple speed owners that using 6th gear in low rpms <3k is dangerous and can throw a rod and blow the motor. I just want to know if it is okay to be in 6th gear around 60-65 mph and to use light throttle in 6th gear for those occasional hill passes around 2500-3000 rpms.
@mattsark
The issue with driving at at high throttle, low rpms is that oil pressure varies with rpm, since the oil pump is speed is tied directly to engine speed. You don't want to load the engine with high throttle input when the revs/oil pressure is lower.
There is also a risk of low speed pre-ignition with turbo charged cars, especially if you like to run the minimum required octane. At 2500 rpm, knock, or pre-ignition, is probably more of an issue than lack of oil to the bearings.
Using 6th gear at too low an RPM will lug the engine down and can damage the bearings. 6th gear is for cruising at speed, downshift to 5th or 4th for passing and hills.
@getawheel
Thank you so much for your quick response. I figured to always use 5th when passing. I guess for those occasional hill climbs I’ll continue to downshift to 5th. I’m afraid of the loads of low end torque on the speeds destroying the rods. I’m going to go into 6th around 60-65 for cruising and will downshift when I want to pass.
I'm not sure of your sources for this information?
I'm a huge fan of your car and it's sister the Mazdaspeed6. The PCM is monitoring boost levels throughout the RPM range. There is no danger to the engine driving in a higher range...probably quite the contrary.
