40+ mpg highway Mazda CX-5
 

I just returned from family vacation from Tennessee to Florida (Navarre) and averaged over forty mpg both ways with pulsing A/C, drafting, wheel covers and upper grill block. Tires had max psi too. I just passed 2k on odometer on this Sport 2 liter manual trans SUV. I'm running just under 3000rpm at 70. Sweet spot is running around 65 on a crowded highway. VERY sensitive to what's in front when I watch the instant readout. Also used nonethanol, hand calculated mileage, which was pretty close to what the dash readout said. City driving was about 36ish. Acceleration was best guess 80% load up to 3000rpm. I'm still learning to drive this thing since it a polar opposite to my old TDI.

That is good work! Create a garage entry for it and record your gas and fuel use on the site!

I found that I'm capable of a 600 mile tank as I finished out the tank with a week of commuting. I filled 14ish gallons with 565 miles on it and two hash marks left on the factory gas gauge. I understand it may hold 18 gallons when filled to the vent. My dash average showed 39.9 but I calculated 37.8 IIRC. Its very hard to get fuel down the filler neck without getting the nozzle cutting out often. I wonder if that skews the station pump readout if you have 6 or more nozzle cutoffs?

I may post some pics as time allows later in an intro thread. I'd like to start compiling data more formally in the future and do some more mods that won't detract too much from the looks. Getting ready for an oil change and another trip that will cover nearly 2k miles very soon.

It might skew the pump reading, but also depending on the car I am told it can mess with the recovery system in the car. Best results always come from using the same method at the same pump. I picked a pump at one of the cheapest stations in the area, and I always go to that pump on a nearly bone dry tank, always pump at the slowest steady fill rate, and always stop filling at the first click. Best we can do to reduce data noise with crude equipment.

Not a good idea to fill all the way to the top as you risk costly emissions repairs when doing so. I go no more than 2 clicks & stop.

Oops, California98Civic beat me to it :thumbup: I agree with the slow fill recommendation. You will certainly get a better, more consistent fill.

Was this running premium fuel? The higher compression (especially Mazda's 13:1) can really benefit from premium fuel.

I'm surprised they aren't capable of low 40s pretty easily. They are nice, though.

Yes, that's a good point not to overfill. In this case, there is enough user's with experience to convince me that it is safe to fill to a point where I can visually see the fuel in the neck, but not so high as to cover the evap vent. Also having a bit of a drive after fillup to settle the fuel further down the neck is recommended as well. I end up having to fill every tank with the nozzle on about the second click in to keep the fuel from frothing up the neck and activating the nozzle stop. It will click and stop almost immediately apon starting a refuel on an empty tank even with taking care not to squeeze too fast of a flow. I've been trained pretty well on fueling quality and station loyalty with the diesel I had before. Poor fuel made a huge difference in my Jetta's mileage. The skyactive engines use piston and timing tech to run 87 octane and vary timing atkinson style to vary compression from 6-13:1 in USA.

I hear you. But it still seems like a lot of process and hassle for a few more ounces to maybe a gallon, and at the cost of irregular fills. Assume you get a whole gallon into the neck, which seems unlikely. Even then it is only 7% or so of total tank capacity. Improve your fuel economy instead by 7%--which is easier than you might think at first--and you'll get all the range back, all the time, without the gas pump hassles and the data irregularity.

Don't Top Off Your Gas Tank! | Mid-Atlantic Air Protection

I would hate for you to learn this lesson the hard way.