My Recent Trip: Expressways…ugh, bad mileage

Tire pressure? Did you check to make sure there isn't anything blocking the vent in the back seat?

 

Did they adjust your tire pressure? Did you check it after?

 

Don't worry about it. With the colder temps this is normal. The heater doesn't affect much since you were driving most of the time. Having the heater on in city driving would drop your mpg since the engine would try to keep warm. Anywho, with the added weight, that also drops the mpg since the engine works harder.

By driving around 5 over you use more gas right there.

By using the cruise control, the engine always try to maintain the speed and if there were any hills along the way which you didn't add gas to, then the engine just mashed it for you to maintain say 70 which adds up to using more gas over several hills. Cruise control is rarely a good choice when going for mpg.

Besides with an mpg of 41.96 you only lost 8.79% mpg from estimated. Remember, the prius c gets 46 on the highway.

If you were in an SUV that gets 30 mpg and you get an average of 27 you may not think it's that bad but it would be worse than what you achieved since it translates to a drop of 10% mpg.

Your biggest enemy is the cold though. No way around it.

Don't worry about it

 

That indicates they adjusted your pressure. I'm "assuming" you normally run your tp higher than manufacturers suggested rate. That will hurt you a little. If they dropped it lower than 30 that will hurt you significantly.

 

65-70 degrees isn't enough to drop it to the low 40s...

 

In Cincinnati it's gotten to the low 40's in the past 2 weeks and even lower recently. The temp set in the climate control doesn't affect it but the outside temperature does.

Also, last friday it was particularly cold throughout the day in chicago. Which is what his location says. Last friday began below 40 and maxxed out to around 45 degrees.

This plus the winter fuel blend doesn't make for the best driving conditions.

 

I read his thermostat temp as his outside air. Sorry.

 

Which is it? Sidewall is much higher than what the owners manual says.

 

my dealer set the pressure at 50 psi, but it seems to be fine.

Nexus 7 ?

 

Yikes...the highest I've had mine is 44 psi, and I could tell it was high because it was on a freak weekend with 70 degrees and electric braking on a straight road wasn't enough, my car just kept on going straight.

On the hottest summer day, I had the A/C up to half and it was 97 degrees and still topped off at 53 mpg. So, I would not be happy with 41 mpg. My first guess is low tire pressure, but it sounds like something else is going on. So to ask Fahfoofnik: Did you have your oil changed at the dealer as well? How high up did they fill the oil? I've heard that too much oil hurts fuel economy. How much of your road trip driving was into the wind?

 

It was the cold weather. Most assuredly.

 

With all that weight in the car, you should be happy, what did you expect to get 60 MPG?
This car with driver only gets me 55 to 60 MPG, on highway. Add a 2nd person and I can get high 40's on the highway.

 

I think it's mostly the speed that's hurting your mileage. Things you can do:

1. Stay to the right and under the limit.
2. Choose secondary, lower speed highways.
3. Drive with load, ie: let your speed fall off on short upgrades, recoup it on the far side.
4. Drive strategically, keep a good buffer ahead (don't sweat it if someone "takes" the space), coast up to slow downs.
5. Raise those tire pressures, moderately at first.