Altima SE V6--best tank: over 40 mpg!

[VegasDude]

I coasted into a gas station tonight and filled up. I very slowly topped off once as I always do.

The final stats for this tank are:
544.8 mi
19 hours 2 min
28 mph average (indicated 35.0 MPG)

Actual 15.345 gal
35.5 MPG calculated (and I didn't round up!)

My MPG increased throughout the tank which could either mean I was getting better at eco-driving, or the reduced weight of the gas itself was increasing my mileage. My driving isn't mostly highway, but it isn't L.A. like traffic either. I just accelerate gently and putt along at 40, trying to time the lights as best I can.

The 3.5 is a great engine. The combination of available power and MPG is one of the best on the road, even 5 years after it was built. I do remember one person online getting 40 mpg at 55 mph from a 2.5, which is certainly powerful enough for this kind of driving.

Could I do better? Definitely. My MPGs started to go up after I increased the tire pressure and I haven't gotten around to changing the oil either.

[ShadeTreeMech]

Originally Posted by SentraSE-R

ROFL! One of the undocumented benefits of hypermiling (POing the gendarmes). If you get 35 mpg, I'm going to wish for a 3.5 engine transplant into my SE-R .

having never heard of gendarmes I looked it up. According to the wiki A member of a gendarmerie; the word is often incorrectly used in English to refer to any French policeman

It seems I have to look up a lot of things while reading this forum. Talk about becoming more educated!

[SentraSE-R]

Vegasdude, Stunning, absolutely stunning mpg from the Altima 3.5. I want an engine transplant into my SE-R .

[VegasDude]

I'm almost ready to fill up again and my car is telling me I’ve averaged 37.3 MPG for the latest tank so far (~560 mi.) It was ~35 the first few days after filling up and gradually increased throughout the tank while my route to and from work and the times I drove it remained the same.

I went back and averaged out the daily temeratures for the last full tank (which was 35.0 MPG indicated and 35.5 calculated) and this one thus far and they were 69.5F over 16 days and 71.3F for 19 days, so I doubt increasing temperatures can account for this. I didn't think about humidity tho...

I'd swear I've been driving exactly the same way so I wonder if my car's computer has adjuststed the fuel usage to better corespond with how gently I'm driving.

[SentraSE-R]

Could be. Either way, you're doing something right.

[VegasDude]

Now that I think about it, there is one thing that's different between the two tanks: my shifting. The first tank I started out shifting 1st-2nd-3rd-4th-5th sometimes skipping 4th if I was done accelerating after 3rd. Over time I changed to 1st-3rd-5th. Given that I'm in 5th before 20 mph, I don't see a reason to shift 4 times to get there. This is on level ground of course. My car has enough torque, and I'm accelerating slow enough, that I can shift at or before 1k rpm without bogging the engine.

Theororetically I should utilize every gear, but it doesn't look like economy is suffering.

[ShadeTreeMech]

I don't see why you have to use every gear. On flat ground i would shift 1st 3rd 5th quite frequently, and cruise in town in 5th. the car would bog down a bit but keep on trucking, unless I came to a hill.

My dad would skip gears in his 18 wheeler whenever he wasn't pulling a load with no problems. Granted those things have 10 forward gears (sometimes more) but still.

[Red Lion]

Editing my reply:

Low RPM is best, but if you're in too high of a gear for your speed, you'll put excessive load on the engine and use too much vacuum, meaning the throttle pedal will be much more open and you'll use more fuel than you should. So find a sweet spot that doesn't lug the engine.


http://ecomodder.com/forum/showthrea...ing-13338.html

[VegasDude]

The mileage computer was almost exactly right this time. It was at 37.8 MPG just before I pulled into the station and then dropped to 37.6 MPG. The calculated total (with a partial fill) was 785.7 miles and 20.76 gal for 37.85 MPG.

[carbonaltima]

That is impressive. The 6 spd se-r's are awesome at mpg on the highway bc of the 6th gear and mpg guage. I haven't been able to get 34 mpg in my 00 and it's a 2.4.