Under the Hood: How many miles driven, and what kind, should dictate oil change schedule

McClatchy-Tribune Information Services

Feb. 11, 2019

Q: If you have a car that doesnít rack up a lot of miles, do you still need to change the oil every six months? I only put about 2,000 miles a year on my car. Iíve heard different opinions on this.

ó Jason P.

A: If those miles are mostly short trips, changing oil perhaps once per year might be a good idea. Iím a believer that miles, and the type of miles driven, are more important than the calendar.

The oil life monitor on my 2 1/2-year-old Chevy Volt, with 36,000 odometer miles, which rarely runs the gas engine (and when it does, itís usually for longer drives with full engine warm-up) is interesting to ponder. The GM monitor uses a complex algorithm based on engine operating conditions to infer oil condition. It indicates my oil life is still 82 percent! Based on this, I wonít need to change the oil even once during the term of my three-year/45,000-mile lease!

Q: I have a 2017 Toyota Tacoma and love it! It came with a trailer hitch but there isnít any place to plug in lights for a trailer. I have a small cargo trailer Iíd like to use with the truck. How do I go about hooking these up?

ó Amy M.

A: This can be a fairly simple process if you buy a custom wiring harness that plugs into the Tacomaís wiring connectors behind each tail lamp housing (connector locations vary by manufacturer). Small trailers (without brakes and a battery charging circuit) typically use a ďflat fourĒ lighting connector. Larger trailers usually employ a larger seven-terminal round connector, so these extra circuits can pass through.

The flat four terminal connector has a brown wire for tail lights, yellow wire for left turn/stop, green wire for right turn/stop, and a white wire for the ground circuit. Trailer lights are configured the same as older domestic vehicles, which used a single bulb for each turn and stop light, requiring an isolation trick within the turn signal switch so a brake light can flash as a turn signal, when required. Asian, European and recent domestic vehicles separate the turn signals and stop light circuits, using two bulbs (typically an amber turn signal and red brake light).

In order to connect a single-bulb trailer to a vehicle with independent lights, a converter is needed to sort out the differing wiring strategies. This little black box is typically integrated into a custom harness (such as the Curt #56282, about $90, for the 2017 Tacoma). What makes this and other custom harnesses slightly less than plug-and-play is a fused 12V circuit needs to be run from the front of the truck (battery or other) to the converter unit. Total install time is about 45 minutes. Itís also possible to purchase a universal converter box such as the Hopkins #48895 converter for about $20-25 and splice directly into the Tacomaís rear lighting circuits/wires. (Donít use those blue quick-splice connectors unless you want to renew them again in about five years!)

For optimal reliability and ease of installation, Iíd go with the custom plug-in type harness when one is available for a particular vehicle. If your trailer uses old-school incandescent lights, carrying spare bulbs is a good idea. The tail-stop/turn bulb is typically a #1157 and side marker/clearance lights are commonly #194. LED upgrade bulbs are available, and they are typically brighter and longer lasting than incandescent bulbs.