Disappointing hwy MPG

In my c I normally drive at 72, sometimes cruise, sometimes not. Average 51 to 54 depending on terrain and conditions. If I slow to say 68 or slower I've managed to average over 58mpg. My worst freeway trips have been at 75-80mpg when late or going up to tahoe. Averaging as low as 38mpg.

 

Any time you drop your highway speed you will improve your mpg, dramatically. I like to abide by the limits, for numerous reasons. And if limits are set high and I'm not impeding anyone, I'll drop down 10 or so.

 

Not so much that they cut cost. It's the prius c, CITY. It's really meant to be the prius for large city dwellers in Japan. not too much high speed there. It's a barely upgraded/changed priusII drivetrain. Between old tech, less aerodynamic styling and being a cheap car of course they aren't going to dump in a ton of money it's basically a niche parts bin car... which is now enjoying mass market appeal and sales numbers.



EVERY toyota for the past 15 years or so is vvti. Some very few are vvtli which IS like vtec... this is NOT a vvtli aka variable valve timing with lift intelligence. Vvti can be just intake (most motors) or intake and exhaust aka dual vvti as seen in new corolla, tundra, etc etc etc. Vvti does not have a different set of lobes just an adjustable cam gear. Vvtli has hydraulically activated system to switch to different lobes.

 

Or just do an end run around the whole situation, choose routes where you can slow down.

 

Yeah he wants best handling prius c but wants lowest lrr tires and won't lower car. I don't think he's much too willing to drive less sporting. Not hating, just observing.



But yes aeromods will help mpg as will hard as hell craptastic lrr tires. But handling will suffer for the worse with both of those.

 

I drive 7 over 90% of the time and get 48 to 54mpg. So I do not know. And 600mi. Phew that's nothing. I've done multiple 7 to 800 mile days



Maybe my rear touring spoiler and mid hatch spoiler help me out at speed, ha ha

 

I posted 7 over. Ha ha.



My longest on 4 wheels was 1400 have done it twice. Longest 2 wheel is about 500. Wrists kill. But yes much more awake.

 

Wow, talk about "one man's ceiling...". My main issue is running the car often enough to keep the battery happy.

 

Work sucks, I put sooooo many miles on my ride for them...

 

Not the man just stupid and twas younger. I routinely get stuck with 700 mile days and gets old. Life is life.

 

Why not add BSFC in the Torque app, formula is on PriusChat somwehre Or you can do it yourself with custom PIDs (engine torque, engine rpm, fuel flow)

 

I think there are more ways to measure fuel flow, there is also option "Enhanced MPG calculation" that may help.

I had custom PID for BSFC and it was bouncing (data delay) around 250-220 g/kWh, almost regardless of rpm.

 

My 46 mile commute is all highway with a 70 mph speed limit. I only have about 3000 mile on my 2015 C4 so far but I notice a 4 mpg increase after the 3rd tank of gas. I currently get 47ish mpg at 70 mph for my commute. I have tried setting cruise to 67 mph just to see if there was any increase in economy, and it has been less than 2 mpg.

But when I put my family in the car to head to a friends house for Thanksgiving dinner, I set the cruise to 75 mph and holy crap does that make a difference. I only added 1 adult and a 30 lbs toddler. For a 36 mile drive I got 34 mpg. On the way home I set the cruise to 70 mph and it came up to 42 mpg.

I realize that this car was designed to be efficient in optimal conditions, and I traded in a V8 Tundra Double cab. As for the efficiency, I notice everything will affect the mpg. Coming from a truck, I was already used to running the speed limit, now I am conscious about getting to my cruising speed. I have owned the car for a little over a month, and have saved $$$$$ that would have been spent on gas. $80+ a week down to $20+ a week is pretty nice. At first I was concerned that I wasn't getting in the 50 mpg range, but I am more aware of how hilly my commute is. I have to agree that it really isn't a highway vehicle, but it is reducing my costs and I have grown to enjoy driving the "little one"