I've been wondering about this for a while. I've done searches, but haven't found anything directly addressing this question.

When the engine is cold, and you're driving on a level road, where in the RPM range should you be shifting (as compared to driving with a warmed-up engine)?

When I've driven automatics, I've noticed that they tend to upshift at a *higher* RPM when they're cold. They also seem to avoid overdrive entirely until they warm up. But to me this is somewhat counterintuitive. Sure, higher RPMs should warm the oil up faster. But aren't they also harder on the engine?

Right now, I shift early if I can (avoid exceeding 4K) and go gentle on the gas. When I stop accelerating, I upshift to get into the highest non-bogging gear in order to keep the engine mellow. Basically, I *never* bog it down when cold, but I also try keep the revs relatively low. After I get my third bar, I'll rev to 6K if needed, and ten minutes later, I feel free to VTEC without guilt.

Is this a good strategy? Or should I stay in lower gears when cold, rather than upshifting?

 

KEEP IT LOW! VTEC limiter on a cold engine is not pretty (it's happened to me a couple of times). I usually never shift past 3.5-4K on a cold start, until I hit 3 bars.

NEVER run the engine fast until the oil has time to travel from the pan and warm!

 

if i can i will usu turn on engine. leave it stationary in neutral for about 60 secs and then granny drive the car (shift at 3-3.5k rpm) for about 3 mins by which temp hits 3 bars then i let one rip!

 

My opinion is the same as yours, Basscase. I keep the revs low without lugging the engine until it is warm.

My theory is that the engine develops thermal stresses and distortion (from thermal expansion) during warmup due to relatively uneven distribution of heat within the engine until the engine is warmed up. That means that stresses will be higher and bearing clearances will be slightly distorted and shifted.

In addition, the oil is not up to temperature which means that the viscosity is increased resulting in reduced flow to vital areas. I would suspect that it would affect the oil passing through the filter as well, increasing backpressure and increasing the risk of a ruptured filter media (or the bypass opens up, allowing unfiltered oil to pass through).

 

My usual shift point is 5k to 6k.

On a cold engine, I'll shift around 3.5k to 4k. I also give it a little more gas, in the hope that the reduced warm-up time will offset any additional wear from the increased load. (No empirical evidence, just speculation on my part.)

 

i usually keep it warming up in neutral untill i see 3 to 4 bars then im off.

 

If I have to let one rip, I usually do it before I get in the car.

 

I'm pretty sure the owner's manual says not to do this.

Generally, I back it out of the garage, and sit long enough to close the garage door (and put the top down, if appropriate). Then I simply drive away and keep it below 3-3.5K RPMs until it's nice & warm (3 bars, at least... and usually a couple of minutes longer).

 

you really shouldn't need to idle your car until you see 3 bars. cold, i shift around 4k.

 

Me too: 3.5k to 4k until the 1-2 shifts are smooth and then.. I shift around the same when the car's warmed up because there's a sh*tload of traffic in my neighborhood! D'oh!