Quote:
Originally Posted by SentraSE-R
I doubt that starting and stopping a warm engine a few times in a minute causes as much wear as running that engine at 2500 rpm for the same minute.
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Well thats where your wrong. Starting and stopping an engine is horrible on the starter, electrical system and engine bearings.
500 revolutions on a surface thats relying on a risidual lubricant film does cause pitting in soft bearing surfaces creating internal friction equal to wind resistance on the outside of a car. This parasitic drag can severly reduce MPG's no matter how you drive as all RPM's are affected.
On the other hand 2500 rpms with your crank floating on a bed of lubricant causes almost no wear at all because thats what it was intended to do then the left .008" inbetween your bearing surface and metal surfaces and then added 50 psi of oil pressure.
I seriously hope your vehicle is not idleing at 2500 rpms as you may have a hugh vacum leak that will cause a sever mechanical failure if you do not fix it soon.
Instead why not tune your idle to a lower RPM and leaner AFR. Most manufaturers stick to around 15:1 or 16:1 in closed loop at idle with no load. You can easily tune this to a leaner 17:1 as long as you adjust for throttle tip in to ensure you do not damage your pistons under load. Assuming gasoline is being used for these AFR's
At these leaner ratios the top of the piston expands more then the shirts of the same piston and could cause scuffing under load. The tip in should compensate with additional fuel to act as a coolant on the piston before timing were applied to increase power.