Just drove return from Toronto to Florida in 2016 ftypr r convertible. Got 29.4 avg mpg - including booting it through one mountain road. Very comfortable and performed incredibly well - including swerving to miss a wheel barrow on highway in Tampa....

 

I am beginning to discover the spousal effect on fuel economy. When my wife is in the car, I can average well over 26 miles per gallon. When not, I usually don't do any better than about 18. I have concluded that her presence makes the car more aerodynamic.

 

LOL

 

When my wife is a passenger, my car has strangely fewer pops/crackles and the exhaust note is a bit muted. Should I contact the dealer?

:-)

 

maybe there's a new TSB out for your wife.

 

Wow . . . I've never come close to that kind of highway mileage in my base V6. The best I've seen was a little under 27 mpg. I suppose I could achieve that by staying under 60 mph.

 

Note that everyone who's checked (including me) has found the reported mileage to be about 2 mpg too high. If you care.

 

Even so 27.4 for an R would be amazing. Maybe they're Canadian miles and the OP forgot the exchange rate.

 

No doubt. I get 27mpg (reported) in my V6, but seldom 30. But I'm sure if I slowed down on freeways and set the cruise control to 70, that it would be up there. But where's the fun in that?

 

They may not be Canadian miles, but they are probably Canadian (Imperial) gallons! US gal = 3.78 litres, Imperial gal = 4.54 litres.....makes a difference. ;-)

Dave

 

I'm regularly getting 29-31 mpg tank average on mostly highway driving from my house to Denver. I really haven't driven almost at all in towns. Speeds are 70+ cruising and ??? when passing. I record all gas purchases and mileage for every tank and calculate it myself. Computer estimates are 2+ mpg too high. Mine is a base coupe, auto. with few upgrades, so I'm a little lighter that most of you. I haven't had a chance to weigh it yet, but I will soon and post the result.

 

Commuting to work some highway, some stop and go highway I get 19 or 20. If I take the back way home (2 lane twisty) once in a tankful it drops to 17. Pretty good for the weight and the power.

 

Average for me, life of car (~8500 miles):

Calculated: 18.8mpg
Indicated: 20.2mpg

My lowest economy tank was 14.9mpg, my highest 22.4. I have not been on any extended road trips, and my commute is pretty consistent. My next fill-up won't be so good though. I had two days where I climbed the hill out of Berkeley quite literally idling in first at 1-2mph.

 

Yep, the difference is a US pint is 16 fl oz, a Canadian/British pint is 20 fl oz, and the rest follows from there.

 

You forgot to mention there's a 2500 foot elevation drop from your house into Denver.

 

Wow! 25+ reported by most of you.

My 15 R Coupe gives me only 14-15 mpg in my daily commutes (2.5 miles in downtown and 4.5 miles on freeway - one way). About 50% of the time I am in Dynamic mode and enjoying what the exhausts have to say that day.

If I do go on longer drives and use cruise control for 65-70 mph, I get 20-22 mpg at most.

Throughout my life I've always seen 15% more fuel usage in my driving - no matter what the car or road. But looks like I am indeed missing on another 20% on this cat.

* All measurements are manual and in US metrics unless otherwise stated.

 

Very astute, but I thought everyone knew that. However, those are mpg's averaged over the tanks, and that's round trip. My destination in Denver is just off the freeway, and I do little driving in the city, less than 5% of the tank.

 

just messing with you.I am quite jealous. I miss my 45 minute commutes up and down N. Turkey Creek canyon into Denver each day in my C4 Vette.

 

Yes. Your wife needs a tune up!

 

When a car equipped with one, it operates on the same principle as a boat anchor.

So far, I don't get better than 25MPG highway average and that is cruise-controlling speed limit.