There was no luggage rack or other changes in the body of the car and the temperature gauge never gets above 1/2 way, but I will check again when it gets colder. I will check on the brakes though. Thanks for the suggestions.
the sticker also gives a variation of the mileage.
It’ll show 28 and 37mpg(sing a preview of a Fiesta sticker) but in smaller print it shows expected range 23 to 33(city) and 30 to 44mpg(highway) for most drivers under both numbers
Hi Myndaa,
I also own an Altima, but it’s an '07 Sedan.
And has the 6 speed manual transmission.
Looking through your posts, I haven’t seen you mention it, but I am assuming that you have a 2.5 S with the CVT transmission. Or do you actually have the V-6?
Where exactly do you live?
Are you in the mountains of Colorado, or the Plains of Iowa?
For the highway decrease that you are seeing, the very first thing that I would do would be to remove and replace the spark plugs, and inspect the ignition coil sticks to see if one is defective.
Next up would be to focus on the brakes.
Since your car has nearly 30k miles on it, I would look at the front and rear pads, and if they have worn away 50% or more, I would replace them. The pads used on the Altima are strange in that when they are new, they are quite thick, and taper in from the pad, so that there is less brake material touching the rotors.
As they wear away, there is more pad material touching the rotors, which could present a slight increase in friction, and possibly a reduction in gas mileage, however slight it would be.
My car has 48k miles on it currently, and has not seen a reduction in gas mileage, but as I stated earlier, its a 4 cylinder manual transmission car.
Here’s the important question I have for you:
What are the engine rpms when you are at 70 mph, with the cruise control set?
I wouldn’t mind comparing it to what my manual transmission gets in 6th gear, and see if your car is revving unusually high?
Also, try shifting the car into manual mode when you are at 70 mph, and manually shift it into 6th gear, and see if that decreases your rpms. If it does, then I would suspect there is an issue with the CVT transmission, and/or its programming, that has lead to the decrease.
Do you remember taking the car to the dealer for a service before the fuel mileage plummeted? They might have changed the programming in the transmission module without your knowledge…
Let me know what your rpms are at 70 mph in CVT and “manual shift mode”, and I will compare them to why my manual car does, and we can go from there to see if there’s an obvious issue that we can take to Nissan. I’ll get mine later tonight (I drove my other car to work today, and its my b-day, so I get to have fun today in the Porsche).
BC.
not familiar with Nissan Altima’s, but do you have a locking gas cap? if not, that might explain a few things, good luck!
If you have a tachometer, keep an eye on that. At 60 mph in a six cylinder, 6 speed auto transmission, the tach should read at or under 2,000 rpm. Lower rpm’s are the key to good mileage and engine longevity. If you don’t have a tach, experience may help. A car that used to run at a lower rpm may feel as if it is operating tight all at once. That means it all of a sudden it starts to feel as if it accelerates faster and slows down quicker in some speed ranges. It just means you missing a gear.
If the car is revving too high and not shifting correctly, bring it in to your dealer and demand that the car gets fixed.
Maybe do that even if you can’t identify the problem.