Warming Up: P&G? PEOG? Steady Throttle?

[JanGeo]

My friends wife has a new Nissan Rouge and is wondering why her mileage is going lower now getting 25 instead of the 26mpg when new. I said you use the remote starter too much!

I find that when I leave his home there is a long up hill drive and taking it at about 10 mph in a high gear really lugging the engine at about 1000 rpm or less gets the engine warmed up pretty quick. It allows more time for all the heat of the combustion to be absorbed in the block and pistons before it leaves to the exhaust. I defineately see more heating of my engine when pulling up a hill than coasting or engine braking. Just this morning I was at 181 degrees and turned the heater on low and dropped the engine temp to 172 and it also raised the idle and increased the fuel consumption at idle.

[bobc455]

Originally Posted by JanGeo

My friends wife has a new Nissan Rouge and is wondering why her mileage is going lower now getting 25 instead of the 26mpg when new. I said you use the remote starter too much!

I find that when I leave his home there is a long up hill drive and taking it at about 10 mph in a high gear really lugging the engine at about 1000 rpm or less gets the engine warmed up pretty quick. It allows more time for all the heat of the combustion to be absorbed in the block and pistons before it leaves to the exhaust. I defineately see more heating of my engine when pulling up a hill than coasting or engine braking. Just this morning I was at 181 degrees and turned the heater on low and dropped the engine temp to 172 and it also raised the idle and increased the fuel consumption at idle.

I believe that part of the dip in my wintertime MPG is due to my remote start. Since I leave my house at 4:45 wearing gym shorts, I start the car for 5-10 minutes beforehand. It's a nice luxury but does require some fuel.

Be careful about too much lugging on a cold engine, your crank & rod bearings might not like it. I'd rather you keep the RPMs up and load down, for better engine longevity.

-BC

[dkjones96]

The only problem with leaving the engine revved up is that the water pump starts going and more water bypasses the thermostat.

I'd more worry about getting a cold engine up to temp too fast by lugging it like that. As long as he has oil pressure the rod bearings should be fine.

[JanGeo]

We don't need no stinking oil pressure I have Synlube - the solid lubricant. Yeah guys the 1.5 liter doesn't strain that much - granted the vacuum is probably pretty low but I don't have the pedal to the floor - I think fuel rate is about 1.5gph or less. If I end up going there tonight and staying over I will see what I pull tomorrow morning in single digit temps. I don't make a habbit of climbing the hill that way but I did notice that it seemed to warm up pretty quick.

[JanGeo]

OK 1000 rpm third gear 1.0gph fuel burn rate temperature rose from about 40F to 93F up the hill outside temps 17F air intake according to Scangauge. Man what a mpg hit I took this morning - the low was 6 degrees. Once I got warmed up for the second leg of the trip into Newport this morning I managed 45.6mpg but I started out at 27mpg for the first several miles. Going slow it definately better for mileage in really cold weather.