Definition of "driving hard" as it relates to oil changes.
 

I get confused with what it means. Is someone who does not race, does not start the car more than 4-5 times a day (daily driving) and only goes fast on open and empty highways (90-120 mph) considered as "driving hard"?

Is someone who does not go over 50 mph in weeks, does not indulge in jack rabbit starts but the route has several traffic lights and stop signs each day, would that be considered "driving hard" and need quicker oil changes?

Or is driving hard a term only used when some takes it to the track or takes off at every traffic light, brakes hard, drifts and such?

Stop and go and sitting in traffic is usually worse because you don't have any airflow through the cooling system and so your engine runs hotter and breaks down the oil faster.

Racing is hard on a car, but at least it has air moving helping to cool it down.

Really though it's all hard on the car as these VQ's run hot anyway. Just check your oil when you fill up and do your oil changes on time and you'll be fine.

I've done a lot of autocross and track days this year on my car but every time I've changed the oil it doesn't look as bad as some of the oil that comes into my buddies shop, and they are just normal commuters.

Depends on who you ask. My definition would include hard acceleration, say 75% throttle or better, which can cause piston ring blow-by and more wear & tear on bearings.

Running hot would be another reason to decrease oil change intervals.

Going by your description, I wouldn't call what you do "hard driving" unless you get hot while waiting at the lights.

It's not "driving hard" per se that I will shorten the interval of oil changes. It's the how hard you worked the engine that I base my oil change interval on. For instance, if I drove 4k miles of mostly highway miles never reving her pass 4k rpm, I will change the oil once. However, if I went to the 1/4 mi track every friday and and put 2k mi in 1 month, I will probably change the oil at 2.5k or 3k mi. The simple fact that at the track, I'm reving the engine up to 7k every gear except 4th (1,2,3 into 4) means the engine was working hard!

Think of it this way, you are working outside and take your time digging post holes for the fence you are putting up. Sure you sweat but not too bad so you shower 1x at the end of the day. On the other hand, your busting your butt with rocks in the soil which you have to use a pick to break apart then dig the hole all in one day, you will probably take more breaks and shower a few times in between just to cool off. Shower = you clean and rest yourself. Oil change = clean engine and get her good and ready for the work ahead (like resting).

Then you have to add in the heat factor. Oil has an operating temp when it works the best. It's something like 190* or something. Too cool/cold and it's thick and don't flow right. Too hot and the oil itself breaks down and becomes less efficient and effective of lubing. So if your driving in the upper RPM ranges, you have extra heat and working the engine harder therefore it's generally a good idea to change the oil at shorter intervals.

YzGyz

You should look at it as "What is NOT driving hard".... Starting your car, warming it for a minute, going onto a highway and cruising at 60, arriving at destination immediately off the highway and parking.

...anything else is driving hard...


Tracy Ramsey

Tracy, the others seem to disagree.

In my case, in city driving, I am quite gentle, my daily commute is about 4 miles with about 5 traffic lights and I do this 4 times a day. On the weekend, I drive out of town and sometimes, I drive at about 100 mph, give or take 20, for about 120 miles perhaps going over 100 mph for 10-15 straight minutes. The car does get hot on these drives but is it hard driving? I have been changing oil every 5000 miles (Mobil 1).

You're over-thinking this. 5000 miles on a high-quality oil is fine. With your 15 minutes high-speed runs, you might want to go with 4k, but it shouldn't be a big deal as long as the oil is staying below 250 F or so.

But you can't change your oil too often. If it's keeping you awake at night, go to 3000 miles.

Edit: If it is bothering you that much, get your oil analyzed.

Blackstone Oil Analysis

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