MPG - 08' 3.5 SE 6sp @ 55 k

[stevewaclo]

Fuel economy does not seem to be a major topic of conversation here, but thought I'd share some numbers on the wife's car (I let her believe that ) and encourage others to weigh in.

Reno has an excellent airport, but getting reasonable fares is a chore and the wife found major savings on a red-eye to Pittsburg out of Sacramento. Filled the car with regular (I know, I know) here in Carson City at about 5000', then up over Donner Pass at around 7400' and down hill the rest of the way to Sac. The trip computer showed 34 mpg on the way over and when I arrived back in CC 5 hours later, the computer said 30.5. Filled up at the same station and squeezed in 10 gallons with 295 miles on the odo. Freeway speed was around 70 on cruise control, with a lot of 45 mph travel around Lake Tahoe. Maybe 60 miles total for those legs.

Around town, the Coupe gets 22-23 mpg.

How are you doing?

[Hussain]

you should have said something and maybe some of the altima coupes in sacramento could have met up with you.... my car isn't running good now. I get about 24 mpg hwy and like 17 mpg city. I used to get 32 mpg hwy and 20 mpg city... I have about 57k or 58k miles

[stevewaclo]

Hussain,

Ouch on the MPG! 17/24 is scary :-(. Did it change to those numbers suddenly?

Obviously your former MPG clearly says the car is capable of decent fuel economy. What were your emissions number last time around ? You aren't banging off those 100 mph quarter miles from every light are you ? Also, how are you measuring your MPG?

Looking at your mods and wondered what Racingline RSB's are. Googled and your earlier post came up. Guessing a rear stabilizer bar isn't killing your mileage :-).

You wold have mentioned poor performance so I presume that's not an issue.

A couple of days ago, I might have guessed a dirty air cleaner but just got an email from Consumer Reports and apparently, within limits, the engine management system can compensate. Performance suffers.

Back in the 70's, siphoning gas from other folks cars was a problem. Inside releases on fuel doors pretty much fixed that.

What's your warranty situation? A trip to the dealer in your future?

Finally, don't have to tell you, but I will, driving technique is a big factor. Maybe you have been unconsciously having way too much fun in your Coupe. Get out your bathroom scale, weigh your right foot and see if been getting heavier :-).

Maybe it's time to start a new thread.

Thanks for the suggestion to get together with some of the Sac owners. Will be heading back next Saturday evening and could come over a bit early.

Best wishes.

[tuhj0k4r]

Dang, I get about 17.2mpg in the city. Since its summer, all I do is work and my job is like a 2min drive from my house. When I do have school, I get about 20mpg. I figured that I get better gas mileage when I'm going about 45mpg in the city (any more or less and my mileage goes down, weird huh?).

[funkee]

The stock air fuel ratios suck. I used to get 23 hwy/17 city. After the UpRev tune, I now max out around 32mpg hwy with cruise control around 55mph and about 20mpg in the city if I'm real gentle. If I'm loving the throttle, I can get it down to about 9mpg.

[SHIFT_COUPE]

After the UpRev tune, this is what I'm getting on the highway...



I do about 19 around town, depends on how I drive

[CoupeVQ35CVT]

I've been averaging 23.5 MPG/40-45MPH on that trip computer display, over 82k miles since '09. I drive roughly 35-45 miles one way to work, 90% on the highway at 60-75 MPH, with the usual 1-2 miles of local neighborhood/office area.

According to the not so usefully labeled live MPG meter, I am evidently close to 30 MPG at highway speeds on level ground.

However, I usually average 430-480 miles on a full tank depending on habits and any other driving locally other than commutes to work. I usually coast when I remember, and accelerate a little hard occasionally.. Vague I know, but just thought I'd share.

I was not aware that an UpRev tune made such a drastic difference or at least it seems like it....
Can those of you who have that done, confirm your "average" display before and after the tune and if your driving has been honestly the same or rougher/route change (more highway now than before?).

I drive 2000+ miles a month so spending $300+ on prem. gas is NOT fun.

[stevewaclo]

Just a reminder that my mileage numbers (30/22) are based on regularly gas, which obviously saves money and still provides plenty of performance for this 68 year old . Would be interesting to do a 1/4 mile blast and see how regular gas performance compares.

Bueller, Bueller, anyone?

Let's consider for a moment. A higher compression engine with premium gas should be fundamentally more efficient at turning a unit of fuel into useful energy (the whole point of higher compression).

BUT, regular gas has more energy per unit of fuel. All other things being equal, where do the MPG/performance lines cross? If I had not just pumped another tank of regular, I'd be able to do the Sac trip on Saturday and let you all know...except I'm also going to Yosemite after Sac. Brother Paul will be there with his family.

Anyone out there explored this? And with all due respect, multiple anecdotes do not constitue data. Serious responses only .

OK, just kidding. All 411 welcome .

Best wishes.

[stevewaclo]

Decided to check in with folks at the American Petroleum Institute on this regular/premium, performance/MPG issue and here's what I learned.

First, premium fuel does have more energy per unit than regular . Wonder where I got that idea backwards?

Also, according to this API article (see Octane), the difference in MPG from using regular in an engine where the manufacturer recommends premium, is, in normal driving, hard to detect.

http://www.api.org/oil-and-natural-gas- ... ctane.aspx

I believe we all agree on the performance difference (still waiting for those 1/4 mile times ) and in the meantime I'll risk getting put on the trailer by an ocassional Ferarri and stick with regular .

Hmmm, not excited about NOX, but it would be neat to have a bit of premium available on demand .

Thoughts?

[tuhj0k4r]

If I'm loving the throttle, I can get it down to about 9mpg.

[SEismyG]

+1 with Hussain

What time will you be in Sac on Saturday? I'm free after 5:30pm and we could do a meet and greet.

[stevewaclo]

Meet'n greet sounds great !

Delta 1110 arrives Sac at 11:45pm.

Don't want to wreck your Saturday night plans but anytime after nine works for me.

Sure you want to be seen with an old guy ?

Best wishes

[SEismyG]

Flying huh? If you brought ur car and came early we could do a semi photoshoot. Idk what's going on Saturday yet but I'll see whatsup. Compare MPG's hahah