Hello again everyone.
Got another question for you all.
So I'm going on vacation in a few weeks, and the drive there involves a lot of open highways, which means a lot of cruise control. I use premium fuel in my car, and I just had the plugs changed out. I'll be getting two new front tires right before I leave. The engine is stock.

Based on all these factors, at what highway miles per hour can I achieve the best overall MPG? As I mentioned, it's all highway driving and I'll have the cruise control on the whole time and probably have the A/C not on and just run outside air for the climate control. I am guessing 70 to 75 mph, but I'd still love to get a reference point.

Thanks all!

 

you are completely wrong on your estimate.. in my s80 70mph gives about 25mpg, 75 drops it to about 22 or 23

Your best speed is actually around 50-55mph.. .but no one wants to drive anywhere that slowly.. Your car has the trip computer, just set the cruise control at various speeds and see what your instantaneous mpg comes up as, and stay at whatever speed you feel comfortable with the figures...

 

Actually, for some reason my car isn't equipped with the trip computer that gives me an instantaneous readout. Would be nice if it did though. Then again, is it possible my car does have it but it doesn't work on account of maybe a blown fuse or it was disabled?

 

For the best mileage, make sure the tires are aired up properly, and do not drive with the cruise on. The cruise can actually waste fuel. It takes time to practice a driving style with a light foot. Also, keep the speed at 65 MPH or less. This will net the best results.