[Blacktree]

Edit: The following is an FYI. It's not a response to anyone in particular.

Just to avoid confusion, load percentage and throttle position aren't necessarily the same. The ECU uses things like throttle position, engine RPM, MAP / MAF data, etc to calculate the load. The load calculation is constantly being updated, and can change from one second to the next, even at the same throttle position. This is where it helps to have something like a Scangauge. Because there's no practical way of knowing the load percentage without instrumentation that can tease that data from the ECU.

Based on what I've read, automobile engines tend to be more efficient at higher load. And this plays into the pulse & glide technique. Basically, you're alternating between peak efficiency or idle. So the engine doesn't transition through the lower load / lower efficiency zones. The brisk acceleration is similar, but you're alternating between peak efficiency or cruise. Although you could P&G when you reach cruising speed.

But there's a catch. Most ECUs will switch to "power enrichment" mode at or near 100% load. The exact amount can vary from one car to the next. As the name suggests, power enrichment mode dumps extra gas into the engine. So if you're doing P&G or brisk acceleration, you may have to walk a fine line between peak efficiency and power enrichment.

That said, I think it should be safe to stay below 90% load. If you have a Scangauge or similar, you can keep an eye on that.