Real World Gas Mileage

[OKVersa]

We are at 918 miles and filled up the car. We got 35.5 MPG. I will be surprised if the next tank is that high, because I think this pump shut off sooner than the other places we'd been getting gas.

I would estimate the driving to be 15%/85% city/hwy. Both city/hwy were running the a/c. Highway miles were between 65-70 MPH.

[BenDupre]

That's why you should keep a gas log and compute your mileage over several tanks. The mechanism that makes the pump shut off is no where near accurate or repeatable.

Ben

[OKVersa]

I was wondering if the difference could be significant between pumps.

So far our fillups have been

34.327.429.428.635.5

That averages to 31 MPG.

Every fill-up was from a different station.

[BenDupre]

Statistically you're compounding the error when you average figures that way. Think about it: I can go squeeze off five gallons into my empty tank and say look I got 60 MPG on that fillup. Then when I average it against the more accurate 30 MPG of my last fillup I now have an average of 45!

The accurate thing to do is to divide all the miles for those 5 fillups by all the gallons for those five fillups. You'll find you have a different number, one that more accurately reflects your average MPG.

Ben

[Ever Victorious]

Statistically you're compounding the error when you average figures that way. Think about it: I can go squeeze off five gallons into my empty tank and say look I got 60 MPG on that fillup. Then when I average it against the more accurate 30 MPG of my last fillup I now have an average of 45!

The accurate thing to do is to divide all the miles for those 5 fillups by all the gallons for those five fillups. You'll find you have a different number, one that more accurately reflects your average MPG.

Ben

Except that if you "squeezed off" 5 gallons into an empty tank and claimed 60 mpg, and then FILLED the tank (by your own words) next time, you'd have maybe 150 or so miles on the odometer, and dumping 13 gallons into the tank, so your calculation for "that tank" wouldn't even bet 12 MPG, and if you averaged that with the so-called 60mpg, you get 36. Not 45.

Yes, doing a one-tank one-reading average is not completely accurate, but it's not as inaccurate as you're all making it out to be. You're trying to take a problem about sample sizes and make it mathematical. Mathematics and statistics are NOT the same discipline.

[c5neb]

We just returned from a day trip to Biloxi which is a 270 mile round trip. The V came up with a solid 34 mpg with speeds between 70 and 80. She did what she was advertsed to do.

[OKVersa]

Actually, the way you suggest makes sense, as does the way I figured the mileage.

Which is why I'm a librarian, not a math teacher!

But it does make sense to do it both ways...keep a record of each fill-up while keep a running log.

Maybe I can get a cute little notebook and pen that will fit in my sunglasses holder which I never use, as I wear them!

[OKVersa]

Will the number be significantly different?

[BenDupre]

EV,

You're right. Calculating MPG does not require statistics. I used (misused)the term generically. Aren't we being a little pedantic?

BUT I am right about the accuracy of the calculation. What we have is more like rounding error. It's caused by the inacuracy of the fuel used data (when the pump clicks off). Using several fills minimizes this error.

Averaging all individual fills improperly weights each equally and causes another error in the calculation. The closer each fill is in gallons the less this error will be.

You can see an example in my fuel log. When I average each MPG figure it gives a totally different number.

Ben

[OKVersa]

Thanks for the log.

But the difference between the running log and the average of the totals is only .7628. IMHO, that isn't significant, since it is less than one mile per gallon.

Or am I missing something?

Thanks!

[Ever Victorious]

I understand what you're saying. Your calculations based on an 8-tank sample and 8 individal tanks averaged are within 4% of each other.

It depends on how much effort you want to put into calculating your mileage over time. I see 4 or 5 tanks in a row coming out to the same calculation at time of fill up, I see a trend. No need to log it. Yeah, I've had a couple tanks that are anomalies, but in the end it all ends up averaging out the same.

[BenDupre]

Well I started doing that because my mileage isn't where I think (or the manufacturer thinks) it should be. I really think there's something wrong with this car. I don't want rounding errors to be part of the problem.

Ben

[XterraVersa]

Not arguing about simple grade school math again are we?

Last tank was 38.6 mpg . But if I rounded it could be 40 mpg

I have filled up at the same pump for every fillup except while on a road trip. Overal the mileage is ~37 mpg

[versawildman]

my milage ratings seem to be around yours or a little less. If i take all seven tankfulls and average them all together I get 26.83 mpg. I still think this is too low for this vehicle. I traded in an '03 Altima (2.5 & auto) on my versa and with the alti I was getting 26-27 mpg, and as everyone knows the alti is alot heavier and has a bigger motor, so simple logic says that it should have been getting worse gas milage ratings then the versa. I have taken the versa back to three dealers for this problem and they all have said the same thing (we hooked it up to our computer and it is running the program as it should) the last service manager that I spoke to agreed with me that thier computer is only going to tell them if the car is running the PCM & TCM programs well or not , not that the programming is at fault, he argeed that the programming could be at fault and that would be a logical reason why one driver gets 25 mpg and another gets 40mpg driving the same model of car. I took that information and called NISSANUSA customer service to file a complaint with them. I spoke to a rep named DEREK TACKETT @ 1-615-725-7837 OR 1-800-647-7261 THEN 7 THEN 2 THEN EXTENTION# 57837 IF YOU DO NOT WANT TO PAY FOR THE CALL. He said that as soon as Nissan gets enough complaints about this they will send out a TSB to address this problem, but if we don't complain they are not going to do anything. SO I AM ASKING EVERY VERSA OWNER TO START COMPLANING ABOUT THIS. my car: sl with CVT in red alert. I now have over 3000 miles on it, so I know it's broke in.
Modified by versawildman at 9:36 PM 9/25/2006

[BenDupre]

Absolutely! Complain!

However, I think we need to get the service manager at the dealer to make the call to the tech center. The techs are pretty well insulated from complaints to the consumer affairs department. The only complaint consumer affairs knows how to process is a dealer complaint (the dealer didn't do what he was supposed to do) etc. I went around and around with them because I didn't want to lodge a complaint about my dealer, I wanted to complain about the product. Finally they took my complaint and pretended it was a product complaint just to get me off the phone. Next day I got a call back from another cunsumer affairs agent and she had "followed up" on my complaint about my dealer... but since there wasn't anything "wrong" with my vehicle...

I'm going to keep working the issue with my service manager. Hopefully I can get him on the phone with the tech center and at least get some other troubleshooting ideas besides "See the number changes so the sensor is working..."

Don't settle for mid 20's mileage in this car. SOMETHING IS DEFINITELY WRONG HERE!

Ben

[versawildman]

Thanks for the post Ben, I spoke to the rep today (Monday) and I have a file # on this complaint so that I have somethi to reference when I call back to complain again.The service guy that I spoke to at the dealer said that he was going to follow up on this and that he would be contacting tech. service to see if there was anything in the works. I told him that I would give him a week to work on it and would be in touch if I did not hear from him before then. So now it is a wait game. Dereck the cust.rep @ Nissan said that the more complaints the faster they will do something-SO COMPLAIN A LOT EVERYONE!

[versawildman]

as a side note to my last post, I work for a large Electric Utility with a fleet of about 1000 vehicles, and I spoke to our service writer and some of our senior mechanics here about this problem and they all said absolutely that there is no reason that Nissan can not re-program the PCM or TCM to achieve the optimum mpg ratings of 32 city & 42 Hwy. and I would have an easier time believing them then someone at Nissan. This car is my 8th Nissan and I have never had a problem with any of them. but if they can't (or won't) fix this problem it will be my last purchase from Nissan.

[datgrl]

Hi folks,

I got my Versa at the end of July. I am a former Scion owner (18months and then I totaled it in a crash). I'm used to seeing 37+from my Scion. I got 43 mpg on a trip to Ithaca, NY.

I drive approximately 60 miles a day: 50 highway and 10 city. I'm averaging 31 mpg. in the Versa SL, CVT.

I coast constantly. On my commute in my Scion, there were specificplaces I would take my foot off the accelerator and I'd fly down thehill. Sometimes I wouldn't have to give it gas to make it up overthe next hill. I'm driving at 5 a.m. so I can time the lights and don'thave to make many stops. Same thing in the evenings. I rarelyhave to stop at lights because they're all timed and I am gaugingit pretty well.

However, in the Versa, I actually lose speed on the downhill. Iwatch the speedometer and see it dropping, instead of picking upspeed. I had to take my car in because the TPMS was malfunctioning.The dealer asked me how I liked the car and wanted to know if Iwas getting 40 mpg. I told him I wasn't and he seemed very surprised.

I'll be calling the CS number to let them know I'm not crazy about themileage. But otherwise (so far), I love everything else about it.

Datgrl in Baltimore
Modified by datgrl at 7:44 AM 9/26/2006

[motoguy128]

The mediocre economy of this car does suprise me a little. I like to compare it to my '03 Toyota Corolla. which is real world driving got 32 city and 39 on the highway consistently. I'm so far getting around 28 city and 32 highway with my Versa. So not too bad really. Lets look at the differences with both 1.8L motors. Electric power steering.

Versa advantages - lighter flywheel, quieter valve train, Fully electronic throttle, 6 speed transmission, very long intake runner (good for midrange and bottom end), more compact motor design & small engine bay (should give better thermal efficiency at start-up)

Corolla advantages - taller final drive, wider spaced gears, 10:1 compression, longer 94mm stroke/smaller bore (good for midrange and bottom end. Almost 200lbs lighter. Undersized A/C compressor.

Both motors have DOHC 16V designs, rear facing exhaust layout which allows longer intake runners and higher exhaust temps (more for emissions), Vairable valve timing, chain driven cams, both cars have 0.31 coeffecients of drag although the frontal area of the Corolla may be less.

My Conclusion - The Corolla is lighter, has slightly taller gearing, less wind drag, Toyota has better fuel management, or the combustion chamber/piston design is superior and allows a leaner mixture without knocking. AN I think the biggest difference is that it's longer stroke desing produces torque more effeciently at low RPM's and partial throttle settings. Remember economy depends mostly on how the engine performs at partial loads and small throttle settings. On the flip side, the Versa feels more responsive at all speeds and is much more fun to drive and the motor is quieter and feels a little smoother. It really sings at higher RPM's, beautiful valvetrain sound, I totally disagree with the negative opinon in most reviews on that point.

Look at the 4 cylinder Altima versus the Honda Accord. THe altima has more power, but the 4 speed transmission has a much shorter top gear and the result is much lower fuel economy. Nissan like Dodge sacrifices economy for performance, but at least the Nissan motors run smooth and well built.

[Althalus]

At a half tank, driving with the windows down basiclly all the time I'm at 35mpg. Driving very conservative (for me) and only really need passing power once or twice.

[tedjamwell]

For what its worth, here are my experiences so far.Best tank - 38.4 mpg. I have reproduced this number, or reasonable facsimile therof, on three fill ups.

Worst tank - 29.2 mpg

Typical average tank - in the 34+ mpg range.

Points of note. My best mileage is achieved using secondary "blue" highways, not interstates. Typically 40 -50 mph (my normal commute). I work nights , so traffic is not usually a factor.

My worst mileage was all highway, very little traffic, average speed in the 70 mph range, however, I was crossing a mountain range at the time while moving my daughter into college with a full load of assorted stuff.

What I have noticed overall is that I do better on the secondary roads than on the highways as a rule. I chalk some of that up to wind drag from the thule rack

BTW, I have an SL with the CVT.

[indus49]

I've got the 4at, which I believe not too many people here have. But with the CVT, it stands to reason you should all be getting mileage in the 30s.

I did a road test under the following conditions:

1.) Work Commute: Approx. 6 mins "city driving": passing eight lights, stopping at approx. half of them, never going over 40mph.

Avg. gas mileage (same gas station, stop at click:) ~28

2.) Visiting my Mom: Approx. 2 hour trip, all highway, few if any exits or changing lanes. Speed: approx. 70 mph.

Avg. gas mileage: ~33

These numbers seem to be close to "on par" with Nissan estimates, although this car is not as good on gas as I, and others, were likely led to believe.

[BenDupre]

About the CVT...

I'm not entirely sure it "should" be getting better mileage. It is the tallest of the three transmissions available, and therefore it CAN acheive better mileage under controlled conditions. But consider the following:

Maybe the CVT, or the profiles controlling it, are too forgiving. When you drive this transmission the first thing you notice is that when you go up a hill it changes ratios to give you more power. If you give it more gas, ratio changes to provide accell, then drops back down when you reach your desired speed. I'm starting to think all this reving up and down might be less efficient although it certainly performs better and easier than fixed gearing.

You'd think changing ratio would allow less fuel consumption than changing throttle opening, but sometimes what you think is not always what you get. I'm just guessing here, and searching for an explanation of my poor results.

Ben

[electech]

I think my mileage has started going up in the last 2 tanks. I am at 3600 miles now and the last 2 tanks have been 33 and 32.7 respectively. I have been able to run more without the A/C unit since it has gotten noticeably cooler here. But, the mileage began to improve after I got ticked at its poor mileage and ran the fool out of it for a whole tank. Every takeoff was firewall throttle, every pass was firewall throttle, every onramp merge was firewall throttle, etc. I told my wife I was going to give it a a reason to only get high 20's on gas!! After one tank of doing that, it improved over 4 mpg!!! I will take it. Now, if I could just get it up to the 36 sticker! It may just be coincendence of getting enough break in miles on it, who knows. I know that I feel less like shooting it now than just a couple weeks ago!!!

[c5neb]

Last fill averaged 34.9. That is an improvement since I applied the new SL badge.

[OKVersa]

LOL! Now everyone will want the badge!

[BenDupre]

I had a talk today with Nick Bunkley of NY TIMES. I have been interviewed twice this week by reporters from NYT: once about my experience with carspace (I also plugged NICO) and once about my decision to purchase a small car. Both reporters asked lots of questions about the car. I was completely straight forward, and I let both of them know that I was happy with the car except for the mileage. I also let them know about the run-around I've been getting from my dealer and NISSAN consumer affairs. I'll have to wait for the stories to print to see what they choose to quote me on. Neither of the stories are about ME so I'll be surprised if they choose to mention my problems. I don't want to trash this car... I love it, really. But I guess I am grinding an axe. I just have to think that if someone: My dealer, or esp. NISSAN Consumer affairs would have listened to my issue and tried to help me get my issue through to the technical people, I might have been able to at least say "The car is only getting 27 MPG on a 90% highway commute, but the manufacturer has been very helpful in finding a solutio to the problem" But alas... Short sighted consumer affairs reps don't see beyond the end of the phone call. Their aim is to resolve the issue by getting you to hang up, not to take care of your problem. Sad thing is they may never know, even if they read the Times article and the print about my dissatisfaction, that they screwed up by not listening to me. Oh well. Ben

[Jim2CPU]

Versa SL w/ CVT4th Tank - 29 MPG

Commuting back and forth to work. 50/50 highway/city.

[tab00]

Date Mile Gallons MPG 7/25 0234 ------- ------- (first fill up) 7/27 0581 11.7970 29.4140 (from Houston to Dallas) 8/02 0810 11.1036 20.6240 (testing performance) 8/05 0944 05.2830 25.3640 8/06 1232 10.6270 27.1200 (trip to Austin, TX) 8/10 1546 10.4940 29.9210 8/17 1789 10.2850 23.6200 8/21 2016 09.1250 24.8700 8/26 2249 10.1690 22.9120 9/03 2427 08.9000 20.0000 9/11 2756 11.2650 29.2100 9/19 2988 09.9200 23.38009/27 3251 11.1400 23.6000

overall average since purchase = 25.10

just for grins I will say that this is 100% "city" driving, never mind the fact that typically only 1.5 miles of my 12 mile commute are not on the highway. Even with this 100% "city" assumption my results have been deplorable. Notice that I have never achieved 30mpg, not even once. I will be calling Nissan to complain again, but I expect that to be fruitless.

I was curious to ask the group, does everyone have the same brand of tire? I have Continental P185/65 R15 86H

This week I am going to drive with GPS, meaning that I am going to reset the trip and fill up at the same time I reset the trip on my GPS. I intend to show the accuracy of the tripometer of the vehicle. (just eliminating possible points of "failure")

I have also noticed the "slowing" issue while coasting down hill. This may be more of a perception than a fact, however it could represent a bearing or brake issue.

I have found so far that when I drive slightly "lead footed" I get milage closer to 20mpg. I suspect that if I really drove it like a ralley car then my MPG would be in the high teens. During normal, fairly conservative, driving I am getting 23-24. If I really, really "grandmother" it I get about 25. even on 100% highway trips I have never hit 30mpg.

[XterraVersa]