Is this mpg right?

[Chris142]

My wife wanted to go to the beach. So we commendiered the mother in laws 17 Sentra. I cleared the mpg at the gas station and hit the road then the hwy. Smooth sailing most of the way. I set the cruise@71 mph.

It says this. Can that be right? Are these accurate? My cars don't track mpg so this is my first time seeing one and seeing this kind of mpg from a car. My Jeep and the FJ are lucky if they hit 16 mpg.

I did not clear the trip meter so I have no way of double-checking it.

 

[wpod]

How much gas did you use to travel how many miles?

 

[Chris142]

How much gas did you use to travel how many miles?

Don't know. Didn't record it. Didn't think about it till I saw the mpg counter lol. Now I'm curious

 

[billt460]

Is that round trip from Apple Valley to sea level and back? Or just one way?

 

[Chris142]

Is that round trip from Apple Valley to sea level and back? Or just one way?

So far just one way.

 

[atikovi]

Seeing the clock shows 3 AM and there is clearly sunshine on the steering column, I wouldn't trust anything that instrument cluster says.

 

[supton]

One way? Could be downhill with a tailwind. And actually true... until you turn around.

Really, the only way to find mpg is to measure several tanks, taking actual gas put in and actual miles traveled. mpg meters are known to lie (to some extent) and what good is a one-time measurement? most are interested in what they can do, day to day. [Anyone can get infinite mpg going down a hill for a short distance.]

 

[billt460]

So far just one way.

If that is showing 51 MPG from Apple Valley to the ocean it could very well be correct. Remember you're going downhill from the Cajon Pass, (4,000 ft.) to sea level at the beach. And that's mostly all freeway at 70 MPH.

 

[Hall]

Can't explain why it's not right, but I would confidently say it's not right. According to fueleconomy.gov, the highest highway MPG for any '17 Sentra is 37 mpg (some owners claim up to 42).

 

[Chris142]

If that is showing 51 MPG from Apple Valley to the ocean it could very well be correct. Remember you're going downhill from the Cajon Pass, (4,000 ft.) to sea level at the beach. And that's mostly all freeway at 70 MPH.

True but I had to go through Hesperia and all 37 lights then it's all up hill to the top of cajon before it drops off. It's not all flat on the fwy. Lots of rolling hills.

 

[billt460]

From my driveway to US 95, (main drag going through town), is around 3 miles, all downhill, (1,120 ft. to 570 ft.). Around a 550 ft drop in elevation. My Jeep will show an instantaneous readout up to 99 MPG. Once I get up 35 MPH and take my foot off the gas, I'll coast all the way down with it pinned at 99 MPG.

Coming back up is another story. I've never reset it since we bought it, and in the last 16,000+ miles I've averaged right around 18.0 MPG. Most of that is around town driving. On our last trip to Kingman and back, (120 highway miles), I managed to get it to creep up to 21.5 MPG.

But after a couple of weeks driving around town, it creeped back down into the 18's again. That's with the 5.7 HEMI running on 91 octane premium.

 

[skyactiv]

Did someone set it to Imperial MPG’s?

 

[Warstud]

Does seem high. Maybe the heat damaged the electronics

 

[AZjeff]

If it turns out to be something close to that on the whole round trip why would you thing about a hybrid?

Chris, fill up now and reset the mpg and trip meters then fill up again back home and calculate the return trip by hand.

 

[PimTac]

Compare the computer mileage to your calculations when you fill up.

 

[Duffyjr]

I've done this with my Lucerne and the computer always reads a little higher than what I figure but there are so many variables it's hard to say. With gas prices the way they are I"m going with the computer, makes me feel better.

 

[Graham Piccinini]

Had a similar CVT Sentra as a rental for couple weeks. That readout always seemed to be about 3-5MPG too optimistic. On a beach trip between Charlotte and North Myrtle Beach it showed 42MPG, both ways. Once calculated at the pump - resulted in 37MPG every time.
All things considered - I can see 45MPG with that (mostly downhill) drive. Going back up will hit it a little.

 

[PandaBear]

You are going from 3k to sea level, that's quite a bit of energy released with 3k drop of height. If you are smooth sailing it is very possible it can get 51mpg, if the sentra is 35mpg smooth sailing at a flat ground.

So if this is the reason, your 51mpg downhill would likely be 19mpg going back to apple valley.

 

[billt460]

I regularly get into the low 40's in my 2018 Camry. High 30's around town. And I run 0W-30, not 0W-16. ( I think the difference would be immeasurable).

 

[MasterSolenoid]

The MPG calculator in my vehicle confuses me.
How far back does the history go?

I believe to use it most practically, you have to occasionally 'reset' it, let's say Monthly.
When I reset mine, the MPG slowly increase to the max I would expect.
Sometimes it goes even higher if I'm coasting.

If the OP reset his, then did alot of easy driving, I could see it going higher then what he expected.
Like other have said, also calculate it when you refill the tank.

Happy July 4th.