Hi,
Coupla thoughts here, none of them original--most have been covered in this thread or others similar (it's one of those "perpetual" topics along with "how much air in my tires" and several others!):
First, for consistency, I'd suggest you check your oil "cold" on a level surface as frequently mentioned in the books. Oil expands and contracts depending on temp, so a "hot" level in most of my cars at night when I come home results in about 1/4 qt lower reading the following morning. Whenever making comparisons, you've gotta use similar conditions. Hot vs hot, cold vs cold, you know what I mean. "Change only one variable at a time" is the way they taught us in school back when we rode our dinosaurs instead of driving...
Next, oil consumption has to be measured relative to a fixed point. That point is wherever the oil registers right after an oil change. If the dealer filled the sump to the full mark, and it's at the low mark in
3000 miles, you're burning a quart in 3000 miles, but if the dealer only filled you halfway between the marks, you're at around a quart in 6000 miles. So you've gotta know where they filled it to start. Which could be ANYWHERE! I've seen cars come out of the shop barely past the low mark, some a quart over the full mark! (One of many reasons I do my own oil changes!)
And lastly, there's no such thing as a "proper" amount of oil consumption. Each engine within a family will burn a different amount under similar conditions, and differing conditions will change consumption within a given engine. As Ed Hayes pointed out, engine braking can increase consumption (due to high vacuum levels), as can high speeds, pulling big hills, hot weather, oil type and viscosity and on and on. While I seriously doubt you'll find ANY manufacturer who will entertain an "excessive" consumption claim until you're going thru a quart/1000 miles (regardless of how that figure was first arrived at), I've seen some German books claim 1 qt/500 mi is normal, and have seen some Japanese engines that burned mere ounces in 6000 miles. For myself, a "healthy" engine usually uses 1 qt/2-3k miles with MY driving style and conditions. YMMV of course!
While I DON'T agree with everything this gentleman has to say, there's some interesting reading here:
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You candraw your own conclusions! Rick