Hi all, new poster here (I think so anyway, since as I started writing this I realized that I couldn't recall if I had ever actually posted anything up to this point).

I have a 2007 Honda Fit, with just over 52,000 miles on it. I've been thinking of changing to synthetic oil the next time I get it changed. I've never run it in a car before though, so I have a couple of questions.

I've heard from a couple of different people that you don't want to change to synthetic oil on higher mileage engines, due to differences in oil density, potential for engine seal leakage, et cetera. If this is true, how high is too high when it comes to mileage?

I am also wondering about any issues there might be with synthetic in the cold. I live in a somewhat chilly place. This last January was our fifth coldest January on record. We averaged -40F on most days at my place, though we had some days where it dipped down to -60F or -63F. I have the usual cold weather accoutrements, battery pad, block heater, and more. How do synthetics perform in extreme cold versus conventional oils?

Side note: On my last car I had a trickle charger on the battery rather than a pad. It kept the battery warm through the charging action, and kept it topped off as well. This is the preferred method up here from what I'm told, since the battery pads and battery blankets are designed for warmer places like Canada. Is there a chance of any negative interaction between a trickle charger and the electronics in the Fit?

My last car had a trickle charger but it was a 1991 with no electronics. I know there are plenty of newer vehicles up here that have the chargers, I ask this question here more for the possible knowledge that any might have as to specific idiosyncrasies in regards to the Fit's electronics suite.

 

No problem switching to synthetic. 52K is not really a high mileage engine. You'll be using a zero weight oil [0W30] and that should perform perfectly. You'll most likely see easier starts, but at -40 everything moves slowly ;-)

I don't think your Fit will see any issues with a trickle charge. Many on the forum utilize them, though not at those temps.

 

Synthetic oil is supposed to be able to handle extreme temps better than conventional oil (thickens when cold and breaks down sooner with heat). As KC said, @ 52k you should be fine.

 

Also... far less paraffin to get chunky when it gets cold.