Need some help! Gas mileage question!

[hydro94530]

Hi all, I couldn't find any info on this so I'm hoping you can help. I've had my Altima Coupe for a month and a half and I love the thing to death. Here's my question; I know the tank is around 16-17 gallons and I'm only getting about 170-180 miles per tank. However its been advertised at around 19 mpg for street and 22 mpg for freeway. Is there something wrong with my car possibly or are the ads way off and this is around what everyone gets out of theirs (I was expecting 300+ per tank)? Any help would appreciated as if it seems like there might be something wrong with mine then I'll need to bring it in today or tomorrow. Thanks in advance.

[SHIFT_COUPE]

CVT or MT? How are your driving habits?What kind of gas do you put in it?

[hydro94530]

CVT or MT? How are your driving habits?What kind of gas do you put in it?

I have a CVT and I only drive 10 or so miles a day on average (I don't leave the city too often). I do live in San Francisco so the bulk of that is on city streets and there are a lot of hills here of course. The mpg still seems low to me but with the info I just mentioned, does it seem right? I also put in premium only.
Modified by hydro94530 at 11:05 AM 6/17/2008

[maxentropy]

I have a CVT and I only drive 10 or so miles a day on average (I don't leave the city too often). I do live in San Francisco so the bulk of that is on city streets and there are a lot of hills here of course. The mpg still seems low to me but with the info I just mentioned, does it seem right? I also put in premium only.Modified by hydro94530 at 11:05 AM 6/17/2008

Personally, I drive very fast and use manual mode CVT all the time. I get 20.2 mpg usually. I do a mixture of highway and backroads driving.

You should expect, at the very least in downtown San Fran 16-18 mpg. And thats if there is a crapload of traffic.

Doublecheck your mileage, there is definitely something wrong if you are getting 10 or so mpg.

[hydro94530]

Personally, I drive very fast and use manual mode CVT all the time. I get 20.2 mpg usually. I do a mixture of highway and backroads driving.

You should expect, at the very least in downtown San Fran 16-18 mpg. And thats if there is a crapload of traffic.

Doublecheck your mileage, there is definitely something wrong if you are getting 10 or so mpg.

Now I'm worried. I will double check to be sure. Is there any difference between regular gas and premium? Does one give better gas mileage than the other? I only use premium and I'm wondering if maybe that's part of the problem as I've heard it can be better to use regular, may not be true. What are your thoughts on that?

[hydro94530]

Just a side note, I have been using the "Range" feature and haven't been following the odometer, so I just reset the odometer and I have about 85% of a full tank so I should get at least 240 miles I would guess. There's also no leaks of any kind underneath that I can see. If this is a malfunction, does anyone know what may cause this low mileage or anywhere on the car I can look for trouble spots?

[quick_shift]

I would use the old paper and pencil method to get a better idea of your gas mileage.

Fill the tank up and write down the current mileage. Drive until its about half a tank, fill up and write down the # of gallons you put in and your current mileage. Then subtract you mileage and divide by the gallons you put in. Or something like that.

[maxentropy]

Good question about potential causes (if you do have an issue).

Could be a bunch of things;-super low tire pressure-dirty air filter-dragging brakes-fouled fuel injectors-spark plugs spacing issue-bad O2 sensor

Honestly, the items above barely happen to most people, but they are all possible. Do you have the 2.5 or 3.5?

I also noticed you've only had your coupe for a month or two. Have you broken it in yet? (driven it hard and fast for a bit)

If not, the engine is still new and you need to clear it out by breaking in the engine. Just be safe about it however you do it.

[hydro94530]

Good question about potential causes (if you do have an issue).

Could be a bunch of things;-super low tire pressure-dirty air filter-dragging brakes-fouled fuel injectors-spark plugs spacing issue-bad O2 sensor

Honestly, the items above barely happen to most people, but they are all possible. Do you have the 2.5 or 3.5?

I also noticed you've only had your coupe for a month or two. Have you broken it in yet? (driven it hard and fast for a bit)

If not, the engine is still new and you need to clear it out by breaking in the engine. Just be safe about it however you do it.

Thanks guys. quickshift, I'll try that with the tank I have and see how it goes. Maxentropy, I have a 3.5 and have been given varying opinions on what type of gas to use and whether it makes a difference. Also, yes the engine is EXTREMELY new. Since I never leave the city I only have 345 miles total right now since I bought it. When would you expect the engine to be borken in. Is it more a sustained speed for a period of time type of thing, or a certian amount miles driven in total? The possible causes you mentioned above seem like things I could check myself, is that the case? If nothing else I guess it would be easily identifiable by a mechanic if there was a problem. The car drives perfectly so I'm hoping it's more related to what you mentioned. Maybe I need to take a road trip, but am I correct in assuming that the gas mileage will go up once I get a decent amount of use out of the engine? FInally, the possible causes you mentioned, would any of these be easily noticed through normal driving? Sorry for all the questions, just want to make sure my baby isn't going to get worse. Thank so far for the help.
Modified by hydro94530 at 2:45 PM 6/17/2008

[maxentropy]

No problems. If I were you, I'd top my tank off and reset the odometer to double check your exact mpg before worrying too much.

Honestly, the things I mentioned are rare cases and happen further down the road. Your car is brand new so it's most likely you just need to continue to drive it and break it in. Plus, you are in high hills and traffic areas so you may likely end up getting 16-18 mpg anyway. Generally I've read that car engines give better mileage the older they are-- it's the other things I mentioned in my previous post that reduce mpg later on.

To break in the engine different people recommend different things- here are a few threads to look at:

http://forums.altimas.org/zerothread?id=322283

http://forums.altimas.org/zerothread?id=333783

http://forums.altimas.org/zerothread/200474

Myself?

GAS: I used to use only 93, switched to 87 4 months ago or so since prices rose and haven't noticed a decrease in performance at all. 3.5's suppossedly provide better performance when you fill them with 93, but 87 will NOT harm the car. Remember, 93 is recommended which means 87 is still acceptable for your car.

BREAK-IN: Like I posted in one of the threads I linked above about breaking your car in-- I drove it like it's stolen Seriously though my recommendation to you is to simply drive your car like you would normally drive it.

Keep us posted and Gluck!

[vballer22]

I know the tank is around 16-17 gallons and I'm only getting about 170-180 miles per tank.

I thought all a/c's had 20 gallon gas tanks? I've got a 2.5 so it could be different, but I thought they shared the same tank.

[maxentropy]

I thought all a/c's had 20 gallon gas tanks? I've got a 2.5 so it could be different, but I thought they shared the same tank.

You are correct, both the 2.5 and 3.5 share a 20 gallon / 75.7 liter tank.

[hydro94530]

No problems. If I were you, I'd top my tank off and reset the odometer to double check your exact mpg before worrying too much.

Honestly, the things I mentioned are rare cases and happen further down the road. Your car is brand new so it's most likely you just need to continue to drive it and break it in. Plus, you are in high hills and traffic areas so you may likely end up getting 16-18 mpg anyway. Generally I've read that car engines give better mileage the older they are-- it's the other things I mentioned in my previous post that reduce mpg later on.

To break in the engine different people recommend different things- here are a few threads to look at:

http://forums.altimas.org/zerothread?id=322283

http://forums.altimas.org/zerothread?id=333783

http://forums.altimas.org/zerothread/200474

Myself?

GAS: I used to use only 93, switched to 87 4 months ago or so since prices rose and haven't noticed a decrease in performance at all. 3.5's suppossedly provide better performance when you fill them with 93, but 87 will NOT harm the car. Remember, 93 is recommended which means 87 is still acceptable for your car.

BREAK-IN: Like I posted in one of the threads I linked above about breaking your car in-- I drove it like it's stolen Seriously though my recommendation to you is to simply drive your car like you would normally drive it.

Keep us posted and Gluck!

No problems. If I were you, I'd top my tank off and reset the odometer to double check your exact mpg before worrying too much.

Honestly, the things I mentioned are rare cases and happen further down the road. Your car is brand new so it's most likely you just need to continue to drive it and break it in. Plus, you are in high hills and traffic areas so you may likely end up getting 16-18 mpg anyway. Generally I've read that car engines give better mileage the older they are-- it's the other things I mentioned in my previous post that reduce mpg later on.

To break in the engine different people recommend different things- here are a few threads to look at:

http://forums.altimas.org/zerothread?id=322283

http://forums.altimas.org/zerothread?id=333783

http://forums.altimas.org/zerothread/200474

Myself?

GAS: I used to use only 93, switched to 87 4 months ago or so since prices rose and haven't noticed a decrease in performance at all. 3.5's suppossedly provide better performance when you fill them with 93, but 87 will NOT harm the car. Remember, 93 is recommended which means 87 is still acceptable for your car.

BREAK-IN: Like I posted in one of the threads I linked above about breaking your car in-- I drove it like it's stolen Seriously though my recommendation to you is to simply drive your car like you would normally drive it.

Keep us posted and Gluck!

Thank you so much, I will go through these and make sure to follow these steps. One thing I find interesting is actually the gas range feature. Let me explain; the reason why I thought it was a 16-17 gallon tank is because when it brought up the whole "low tank" warning saying I had 15 miles left, I went ahead and filled it up and it only filled up to 16 gallons. I'm now wondering if I actually had 3 gallons left and the thing is just way to sensitive. I'm now thinking I might of had another 40 or so miles left. I'll do what you said though and top it off and start over and see. Is your're low gas warning just as finicky? I would figure that if it really was that low it would tell me on the last half a gallon or so. In any event thank you for the tips and I'll post back here after I tryt his out, hopefully Ill be good for the next few weeks

[hydro94530]

Maxentropy, just checked out those links, great advice. Since I don't leave the city too much, I think I'll take a nice drive once a weekend for the next few months. Maybe like a 90 mile round trip and see how it goes. Still wonder about that damn low fuel warning tho.

[maxentropy]

Maxentropy, just checked out those links, great advice. Since I don't leave the city too much, I think I'll take a nice drive once a weekend for the next few months. Maybe like a 90 mile round trip and see how it goes. Still wonder about that damn low fuel warning tho.

My pleasure boss. The low gas indicator usually comes on for me when I've got 40 miles or so left as well. Better to know sooner instead of ending up with an empty tank of gas!

[hydro94530]

My pleasure boss. The low gas indicator usually comes on for me when I've got 40 miles or so left as well. Better to know sooner instead of ending up with an empty tank of gas!

Okay that make sense, I guess that would at least put my total mileage to about 210-220 right now. On some of those links you sent, they mentioned using manual for a while, you think that holds any water?

[xeene]

driving on hills will kill your mileage. with 3.5 engine you're getting normal results. the tank is 20 gallons total out of which 3 gallons are for emergency situations that's why the fuel gauge and computer will say empty when you've used up around 16-17 gallons. cycle through your computer info and see what's your mpg and mph average.

[hydro94530]

QUOTE=xeene]driving on hills will kill your mileage. with 3.5 engine you're getting normal results. the tank is 20 gallons total out of which 3 gallons are for emergency situations that's why the fuel gauge and computer will say empty when you've used up around 16-17 gallons. cycle through your computer info and see what's your mpg and mph average.[/QUOTE]

I think I tried checked that and it said around 10 but I may have been looking at the wrong thing. I know tho, the city is probably a big factor. I'm going up and down hills 90% of the time.

[08altima35]

i grew up in san fran and know that the hills in the city will absolutely destroy any kinda gas mileage your car is capable of. the manufacturers advertised city mpg was not intended for san fran hills dude. i doubt you would even get 15 mpg if you owned a yaris and lived in north beach.

[hydro94530]

i grew up in san fran and know that the hills in the city will absolutely destroy any kinda gas mileage your car is capable of. the manufacturers advertised city mpg was not intended for san fran hills dude. i doubt you would even get 15 mpg if you owned a yaris and lived in north beach.

Yeah that seems to be the case so far. I'm still going to take some drives on the weekends and track the mpg carefully just to be sure though. The mpg/mph on the display is actually showing only 8/8, so I'm not totally convinced that nothing's wrong.

[LongBeachCoupe]

Everyone is forgetting the golden key.. that the computer counts sitting time...

If you have your car sitting in your driveway running (waiting to pick up a friend) that time standing still, is calculated into the cars avg MPG, and your avg spd and MPG will decrease accordingly.

Hills KILL! To see how that works, reset your mpg at the bottom of the series of hills and ride it up, see what it tells you. Now if theres any lights on the hill, your burning more too!

[hydro94530]

Everyone is forgetting the golden key.. that the computer counts sitting time...

If you have your car sitting in your driveway running (waiting to pick up a friend) that time standing still, is calculated into the cars avg MPG, and your avg spd and MPG will decrease accordingly.

Hills KILL! To see how that works, reset your mpg at the bottom of the series of hills and ride it up, see what it tells you. Now if theres any lights on the hill, your burning more too!

Interesting, good point LBC, didn't think about it that way.

[LongBeachCoupe]

i realized this because i wanted to see what the MPG would be going to Carlisle from my friends house... I was waiting outside for him for a half hour... and i noticed when it said i was getting 3 mpg!

[hydro94530]

i realized this because i wanted to see what the MPG would be going to Carlisle from my friends house... I was waiting outside for him for a half hour... and i noticed when it said i was getting 3 mpg!

Yeah that makes sense since it has to calculate everything from the moment the engine is on. For me, every morning I warm up my car for a good 8-10 minutes, so idling like that every morning definitely would have an effect I suppose. Do you guys think warming the engine up in the mornings is even valuable? I always hear varying opinions on whether it matters or not. I hear it's good to do it at first while your breaking it in, but I'm not sure if even that is correct or not.

[LongBeachCoupe]

DO IT... especially before you hit 2k miles...

its best to let the car heat up till it idles at 1k rpms

[hydro94530]

DO IT... especially before you hit 2k miles...

its best to let the car heat up till it idles at 1k rpms

Nice, been doing it so far, so I'll keep it going. Thanks dude

[xeene]

how cold does it get in cali? warming it for 8-10 min? i've never done that long in -20 windchill michigan winter. when your rpms hit 1k, you're good to go. stop wasting gas!

[hydro94530]

how cold does it get in cali? warming it for 8-10 min? i've never done that long in -20 windchill michigan winter. when your rpms hit 1k, you're good to go. stop wasting gas!

Its actually always pretty warm here. I don't time it, I just watch the temp gauge and warm it up until it gets to the middle, or where the gauge normally sits while driving. No need to do it for that long? I honestly have never watched the tacometer before while warming up, is that the best way to go?

LOL on the emoticon btw, that's a good one. Been feelin like that recently.

[LongBeachCoupe]

your car doesnt need to be mid temp to run safe...

Just wait till it hits 1k

[hydro94530]

your car doesnt need to be mid temp to run safe...

Just wait till it hits 1k

Cool, learning a lot here while sounding like noob too, lol. Thanks though, that should help with gas too of course.
Modified by hydro94530 at 3:27 PM 6/19/2008