MD 40 MPG Road Trip How to Rating Options

[Kate31]

When I check mine in comparison to the actual MPG is get less than a 1.0 mpg so I would say at least for my car, I can trust it!

I still love this write up Amanda...was tempted to do one for my big 3,000 miles but still have yet to do so.

[rexerex]

Does anyone have experience or true knowledge about switching back and forth between neutral and drive? I was told frequent switching between neutral and drive is hard on the transmission so I don't do it. Is this true?

It appears to be debatable. Deceleration with the transmission engaged will shut off modern electronic fuel injectors as opposed to them using fuel at idle rate in neutral, so no fuel savings if coasting in neutral. Transmission wear may be increased by doing it, but there's lots of debate about that. Plus it could even be illegal according to some people. The reasoning is if the engine stalls you will lose power steering and brakes which could be dangerous.
Very little fuel savings if any for most drivers so leave it in gear until you learn different.

[omar]

I moved from Pittsburgh to Cincinnati OH where I do not have as many hills as they were in Pittsburgh. I have tried everything to get good gas milage but I can't. I have tried to accelerate before going UPhill, get momentum & then leave car in nuetral and engage back again once I am up the hill but the gain in gas milage is not worth the effort doing it every time. Putting in Neutral both uphill and downhill improves gas milage a lot but it is a lot of effort to do.

Here is what happens.

If I fill a gast tank on the side of interstate and go staright to interstate drive b/w 55-60 MPH at RPM <2000 I will get 39 - 40 MPG. After driving 30 miles on interstate, as soon as I leave interstate and drive 1mile ONLY again ONE MILE ONLY in the city - MPG drops to 29 MPG.

By doing using nuterals uphill or downhill I gain an advantage of 3-5 MPG so Interstate becomes 43-44 MPG and adding 1 mile of city driving will make it 32-33 MPG.

I have stopped putting car in neutral as gaining 3-4 MPG is not worth the effort as I had bought Elantra with Advertisement of "40MPG" I thought going 1 mile on inside roat may drop it to 36-37 MPG & not 29 MPG. Also putting car in neutral while going downhill makes it a free rolling ball as otherwise Engine RPM would slow the car decreases chance of accidents. (I work in Trauma Center so I know what car accidents can do - gaining 3-4 MPG is not worth the risk)

As far as Manual is concerned - I cannot upshift the car until car computer allows me to do it. It is not exactly same as driving "Stick Shift" but I will try Manual and see, if I can get any advantage on MPG.

[Red Elantra GT]

Hey-it's always best to drive the car, starting with a full tank, and fill it when needed, and then do the math to figure out the mpg. I would never rely on a "mpg meter" to know the true mpgs.

[Alex2013GT]

I moved from Pittsburgh to Cincinnati OH where I do not have as many hills as they were in Pittsburgh. I have tried everything to get good gas milage but I can't. I have tried to accelerate before going UPhill, get momentum & then leave car in nuetral and engage back again once I am up the hill but the gain in gas milage is not worth the effort doing it every time. Putting in Neutral both uphill and downhill improves gas milage a lot but it is a lot of effort to do.

Here is what happens.

If I fill a gast tank on the side of interstate and go staright to interstate drive b/w 55-60 MPH at RPM <2000 I will get 39 - 40 MPG. After driving 30 miles on interstate, as soon as I leave interstate and drive 1mile ONLY again ONE MILE ONLY in the city - MPG drops to 29 MPG.

By doing using nuterals uphill or downhill I gain an advantage of 3-5 MPG so Interstate becomes 43-44 MPG and adding 1 mile of city driving will make it 32-33 MPG.

I have stopped putting car in neutral as gaining 3-4 MPG is not worth the effort as I had bought Elantra with Advertisement of "40MPG" I thought going 1 mile on inside roat may drop it to 36-37 MPG & not 29 MPG. Also putting car in neutral while going downhill makes it a free rolling ball as otherwise Engine RPM would slow the car decreases chance of accidents. (I work in Trauma Center so I know what car accidents can do - gaining 3-4 MPG is not worth the risk)

As far as Manual is concerned - I cannot upshift the car until car computer allows me to do it. It is not exactly same as driving "Stick Shift" but I will try Manual and see, if I can get any advantage on MPG.

Didn't you buy a flood damaged car? It seems EXTREMELY strange that the computer would drop from 39-40 MPG after 30 miles of driving down to 29 MPG after only one mile, that is unless that one mile takes 30 minutes to drive. If that is happening it sounds like there might be some sort of an issue with the car? Do your hand calculations reveal the same drop?

[Silentwolf]

I moved from Pittsburgh to Cincinnati OH where I do not have as many hills as they were in Pittsburgh. I have tried everything to get good gas milage but I can't. I have tried to accelerate before going UPhill, get momentum & then leave car in nuetral and engage back again once I am up the hill but the gain in gas milage is not worth the effort doing it every time. Putting in Neutral both uphill and downhill improves gas milage a lot but it is a lot of effort to do.

Here is what happens.

If I fill a gast tank on the side of interstate and go staright to interstate drive b/w 55-60 MPH at RPM <2000 I will get 39 - 40 MPG. After driving 30 miles on interstate, as soon as I leave interstate and drive 1mile ONLY again ONE MILE ONLY in the city - MPG drops to 29 MPG.

By doing using nuterals uphill or downhill I gain an advantage of 3-5 MPG so Interstate becomes 43-44 MPG and adding 1 mile of city driving will make it 32-33 MPG.

I have stopped putting car in neutral as gaining 3-4 MPG is not worth the effort as I had bought Elantra with Advertisement of "40MPG" I thought going 1 mile on inside roat may drop it to 36-37 MPG & not 29 MPG. Also putting car in neutral while going downhill makes it a free rolling ball as otherwise Engine RPM would slow the car decreases chance of accidents. (I work in Trauma Center so I know what car accidents can do - gaining 3-4 MPG is not worth the risk)

As far as Manual is concerned - I cannot upshift the car until car computer allows me to do it. It is not exactly same as driving "Stick Shift" but I will try Manual and see, if I can get any advantage on MPG.

I cannot see how putting a car into neutral (even an A/T) requires THAT much effort. Push button in and push it forward one notch......

Secondly, the car is NOT a free rolling ball. Brake modulation on the downhill side works wonders, and some of that momentum gained on the downside of one hill could easily translate into the next hill (if close to first one). The driver prevents any mishaps, NOT the engine or car. What the car will do is prevent serious injury in case there is an accident.

[IHeartMyRedCar]

To keep the car from auto downshifting on a down hill, put in manual and leave it in 6th. It will stay in 6th gear every time and will not down shift causing you to loose momentum.

[malawibob]

Great report Amanda. How about this one from the other end of the universe.....Florida. (We don't have hills of any consequence). 2013 Elantra Limited with about 3600 miles on it now. My best mileage was 44.9 at 65mph average. On a 44mph road I can hit over 40mpg every time. At 70mph on interstates I get around 39mpg. Someone tested a bunch of cars and found that the Elantra can only get 40mpg below 74mph, so I tested it and found I can get increasing mileage indications at 77mph. (Didn't keep it there for long so I don't have final figures). I always drive with cruise control on but with eco off. (I said Florida doesn't have any bad hills).

On another note I wonder if anyone else is having an accelerator problem? I had 2011 Hybrid Sonata that was flat out dangerous because it sometimes took over 2 seconds to respond to accelerator pressure. Dealer told me that was normal?!? When asked what he could do for me I told him sell it and immediately took a trade to 2013 Elantra. It also has hesitated responding to accelerator pressure when making a sharp turn. I have to turn from a 90 degree driveway onto a 6 lane highway and believe me you do not want a hesitation in response to pushing, (even gently), on the gas pedal. I believe Hyundai has an engineering problem with the fuel flow that makes their cars dangerous!

[elantraguy241]

I find Serenity to be quite peppy with small inputs on the accelerator pedal. Eco modes kills the response, but you said you have it off.

[henryd1981]

On my day trip to Oklahoma on Thanksgiving, my overall mileage on the tank, with mostly highway driving, was 33.9 mpg according to my Gas Cubby app. The MPG display on my dash went on a downward trajectory on the way back home. The drive had plenty of hills and my destination had a higher elevation than my starting point. I stayed close to the speed limit, maybe going 3 over at most and used cruise. Also, I had a headwind driving home. Temps were in the low 70s that afternoon.

I have plans to go to Waco in the near future. I plan to check the mileage again since it's flatter terrain than heading to Oklahoma.

[Silentwolf]

Great report Amanda. How about this one from the other end of the universe.....Florida. (We don't have hills of any consequence). 2013 Elantra Limited with about 3600 miles on it now. My best mileage was 44.9 at 65mph average. On a 44mph road I can hit over 40mpg every time. At 70mph on interstates I get around 39mpg. Someone tested a bunch of cars and found that the Elantra can only get 40mpg below 74mph, so I tested it and found I can get increasing mileage indications at 77mph. (Didn't keep it there for long so I don't have final figures). I always drive with cruise control on but with eco off. (I said Florida doesn't have any bad hills).

On another note I wonder if anyone else is having an accelerator problem? I had 2011 Hybrid Sonata that was flat out dangerous because it sometimes took over 2 seconds to respond to accelerator pressure. Dealer told me that was normal?!? When asked what he could do for me I told him sell it and immediately took a trade to 2013 Elantra. It also has hesitated responding to accelerator pressure when making a sharp turn. I have to turn from a 90 degree driveway onto a 6 lane highway and believe me you do not want a hesitation in response to pushing, (even gently), on the gas pedal. I believe Hyundai has an engineering problem with the fuel flow that makes their cars dangerous!

I'm surprised your getting that good of mpgs on Florida gas.

[roydjt]

On another note I wonder if anyone else is having an accelerator problem? I had 2011 Hybrid Sonata that was flat out dangerous because it sometimes took over 2 seconds to respond to accelerator pressure. Dealer told me that was normal?!? When asked what he could do for me I told him sell it and immediately took a trade to 2013 Elantra. It also has hesitated responding to accelerator pressure when making a sharp turn. I have to turn from a 90 degree driveway onto a 6 lane highway and believe me you do not want a hesitation in response to pushing, (even gently), on the gas pedal. I believe Hyundai has an engineering problem with the fuel flow that makes their cars dangerous!

Is this with an automatic transmission? The delay you are experiencing may be due to the transmission shifting into another gear, which can take a fraction of a second but feel like quite a bit longer. The Elantra's throttle is drive-by-wire (in the MD/UD and newer for sure, I think it is also in the HD), but the response should be pretty much instantaneous. However, the ECU can delay the throttle actuation to allow the transmission to shift into the best gear.

-Roy