200mph

My son and I just finished his school science project using our 2013 Q5 3.0T...

Whether premium gas is worth the added cost?

I drove a 70 mile highway route (Winston-Salem to Charlotte Motor Speedway) several times each way with regular and several with premium. We only measured long runs of uninterrupted cruise control use, set 5 mph above the posted speed (mostly 65 posted, so 70mph).

Using the onboard trip computer, with regular gas, we averaged 27.8 US mpg. With premium, close to 29mpg.

So, while the ECU adjusted for the higher octane fuel and delivered better mileage, on a cost per mile basis regular clearly gave the best results.

Hope that's helpful.

200mph

While I cant speak to the accuracy of the trip computer, it didn't matter for his experiment, because the use of the same trip computer was a constant, not a variable being measured...

However... know that as fuel mileage increases, the increments that the trip computer measures also rises...

starting at 0.1, then 0.2, etc. In the high 20's it wont calculate every tenth on a MPG change, just every three tenths.

So if it reads, say 28.5, your actual average could be 28.5, 28.6 or 28.7, because the reading wont change until you hit 28.8.

At the extreme, if you reset it while coasting downhill, it jumps from 98 MPG right to 102, then 107.

Interesting, just not finitely accurate !

mrrun2fast

I'm on fuelly and it's interesting how much lower user experiences are compared to the estimates. I'm slightly disappointed that I'm not nearly anywhere near the estimated mpg with my 2.0T.