4700 RPM all day on 5W20?

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"If it takes 71 BHP to push the car the stress is that of 71 BHP regardless if the engine can produce twice that at sea level, or just that because of the high altitude. No worry in my book."

From what I can recall when driving over long, high altitude passes in CO and CA, 71 hp on level ground at sea level seems different than 71 hp on a steep grade at 11k ft with a headwind. On the bikes I never had a problem, just give it a bit more throttle, but it certainly didn't have the passing power that I was use to. In the truck again I need a bit more throttle, and from what I've been told (I don't have an egt gage) the egts can climb to maximum levels as the turbodiesel is working much harder in those conditions. I do recall seeing station wagons loaded for vacation, barely making 50 mph up the passes, probably with wide open throttle.

One needs more power to do a grade at the same speed as on level ground, but even if one willing to keep hp the same and let the speed drop the engine is working much harder.

On a different subject, with a given accident rate one will see more deaths and serious injuries at higher speeds. There are other factors to consider, car makers and the NHTSA have been working on decreasing that injury and fatality rate for decades, but speed is still the primary driver. Imagine bumber cars at Disneyland if they accelerated 0 to 60 in under 3 seconds like some bikes; would there be a few more injuries ?
 
1sttruck, those grade observations mirror mine. Also, the rates are death rates, not accident rates, and your premise that speed kills has been demonstrated by the Federal government for decade after decade to be false.

jmacmaster this is so far OT and prosaic that I find it warrants no further attention from me.
 
5th gear is .755. Final drive is 4.388. Effective final drive is 3.3129. Stock 205-50-17 tire turns 804 revs/mile. Engine turns 2664 revs/mile which is also its RPM at 60 mph.

OP is proposing driving 101-107 MPH minus what he loses with thinner-than-50-series tires.

Someone will check my math I'm sure.

mazda spec page
 
We have gone so far off topic this is going to nap. Thanks for the info on the speed laws in Montana though, as I never knew why it was changed.

Thanks
 
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