Hey guys I looked in the stickies and didn't find anything on on gas mileage. I just wanted to get everyones opinion on gas mileage tips. I know one is to have proper presure in the tires. I want to maximize my mpg. Please post your gas mileage tips.

 

This is discussed on a regular basis in either the 4th GEN or 5th Gen Forums.

Tire pressure
Premium gas
Regular oil & filter changes
Air Filter
Fuel Filter
Cruise Control
Light foot
Chevron Techron before oil change
No air conditioning
Roll windows up
New PCV valve if engine hesitates
Transmission fluid

etc. etc.

 

search search search search.

common sense. common sense. common sense. common sense.

 

Is there a 300z or 350z fuel filter that gives better mileage?
When you say engine hesitation does that mean when you push on the gas it waits a few seconds to do anything?

 

Yes, also known as throttle response. This can also be remedied by cleaning the throttle body with throttle body cleaner as outlined in the stickies or motorvate.ca.

Some .orgers have switch to a 300ZX filter which does not improve fuel economy. Since its larger you can go further before changing it.

Transmission fluid and fuel filters should be replaced every 30K. That is also the recommended replacement interval for replacing air filter but I've never been able to get that many miles out of one. I've since switched to a K&N panel air filter which may have improved my fuel economy modestly. Synthetic oil apparently benefits fuel economy but I haven't switched to it - I put too few miles on my Maxima to justify it.

 

According to the Haynes manual, another culprit can be the emissions system not functioning properly. See the stickies for checking/cleaning the EGR valve and of course faulty 02 sensors contribute to poor fuel economy.

An application of SeaFoam through the brake booster hose cleans out the intake manifold which would likely help fuel economy.

 

Thanks that is very good information. The reason I ask is I was getting 325 to a tank city driving now I get maybe 300. It all happened when I put a CAI and a full cattman exhaust. I thought that would make my mileage better. My A/C definately works better because of the exhaust. weird. I was really into the petal at first with all that extra power but now im back to my regular driving habits.

 

Like what they said up there.

I get 400+ Miles on 10 gallons of gas.... Just ask me how.....

 

i just noticed the other day that there is a sticker on the inside of the fuel door saying premium gas. haha oh wells no knocking, yet.

 

how can i change my heavy foot to a lighter one? can it be cleaned?? duuhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

 

It's not often that RM says something wrong, but unfortunately, he is wrong about premium contributing to fuel economy.

"Premium gas does not boost fuel economy or power."

http://www.cbc.ca/news/background/co...gasmilage.html

 

So the timing adjustment that must occur to counteract knock has no impact on fuel consumption?

 

Thank you, sir Frank! Now I feel justified in running 89 octane (more recently a newly-introduced 90 octane), 80% of the time, because I can't tell the difference.

 

Using a HIGHER octance than specified won't improve your fuel economy, but using a lower one than specified will hurt your fuel economy because your engine will retard the timing when it senses knocking.

 

That's what I thought. So rmurdoch was right.

 

Anybody who runs premium fuel for commuting purposes or mostly city driving is wasting their money, IMHO. Use 89 in the city. Perhaps if you're on a road trip in the summer time and are loaded down and doing a lot of climbing in hot weather, you'll notice a difference in using premium gas. That's the one and only time I've ever noticed any pinging on 89 octane.

 

rmurdoch - I typically agree with what you say, but I'm going to have to disagree here. There is a distinct performance difference between the 87/89 and 91/93 octanes (87,89,93 is all I can get around here). The reason you don't notice any pinging with the 89 octane is because your knock sensor is retarding the timing (as it is supposed to). The engine was designed to operate on 91 octane fuel, and I don't see why anyone would choose to run it any other way. The savings per tank are about $2 (USD). Even at 2 tanks a week, that amounts to $200 a year. That doesn't even take into account any possible gas mileage increase you might get from using the higher octane fuel.

Just my two cents

 

You have to remember, murdoch is in Canada where the gas is different. The additives are different which allows him to run the lower octane stuff without issue.

As for tips:

1) Keep it under 3,000rpms
2) Smooth acceleration, not sudden bursts and coasting
3) Cruise control when on the highway
4) Regular tune-ups

 

That explains it

No, seriously, good point THT.

 

THT is bang on. Apart from the pinging incident mentioned above, the only other time I have had engine ping was about 3 months ago. I had filled up with Chevron 89 octane in Blaine, Washington, and booted my car on the freeway a day or two later and got some engine ping. When I do fill up across the line, I always bought premim gas except for this one instance.


Why you ask? Because a lot of Canadians experience crappy performance on US87 octane gas, despite their car running fine on it in Canada. I guess the same may be said for 89 in my Maxima.

We have more additives in Canadian gas and I strongly suspect you would find your Maxima ran better on Canadian 89 octane than US89 octane. I ran Chevron 92 most of the winter. Perhaps the car pulls a little harder when you get into it, but its not really noticeable for me.

The cost differential between mid-grade and premium here is 5 cents/litre or at current exchange rates about US$0.16/US gallon. I am currently running Husky 90 octane which is sold by them at 87 octane prices, or US$0.36/US gallon less than 91 or 92 octane anywhere else. So I am saving in excess of US$6/tank by running Husky 90 ocatane gas rather than Chevron 92, Shell 91, Petro Canada 91, Esso 91. We don't have 93 octane here, but have 94 at a few stations at a higher cost than premium.

Anyone want to race, lol!

Edit - I have also gotten 550 miles to a tank 3 times on 89 octane and in excess of 500 miles to a tank on 89 octane at least 15 times on highway trips to the Okanagan - say 600 miles+ round trip, climbing from sea level to 7,000 feet in elevation, down to 2000 ft at destination and back up to 7,000 and down to sea level on return trip - generally no faster than 75mph with cruise control on.

PS The fluid comparisons are better when beer is compared, lol!

 

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I agree, though, that most gas mileage tips are common sense. I did find my mileage improved significantly when I started monitoring my tire pressure more closely.

 

shift at 2,500rpm and drive under 2,500 rpm all day

 

Keep it under 3k rpm? You might as well drive a civic.

Damn no sudden bursts and coasting... i love doing that...

If your so concerned about gas milage seriously whats the point of owning a max... Tho it can get decent gas milage there plenty of other cars out there that beat it.

 

There's plenty of power below 3K for daily driving.

 

That's right. I'm at 70MPH in 5th gear at just under 3K and that's over the speed limit by 12% (112KMH in a 100KMH zone). Anything faster and not only does fuel economy suffer but so does my driving record.

 

ya i drive the max to rip her up, if i wanted gas mileage i would get something else. heck trucks get 12 mpg so at 20+mpg i dont mind it.

 

dont drive

 

Hmm... about 6 weeks ago I was getting about 20 mpg in mixed driving (mostly city traffic, some highway). It's weird for the past 6-10 months, it hasn't mattered how "fuel efficiently" I drove, I haven't gotten better than 22mpg nor worse than 19 mpg.

Since then, I have replaced the knock sensor, PCV valve, fuel filter, and all three O2 sensors.

At my last fuel up on Sunday, I measured 25 mpg over 400 miles, 275 of which was interstate driving averaging between 72 and 75 mph, and the remainder was in mostly city traffic.

I am completely shocked by the difference in mpgs I attained. Considering I have a '96 GLE w/ 133k on it, I think that's pretty good. I figure if I were to take an interstate trip in it, averaging about 60-65 (hah!) I could probably get the mpg up to around 28 easily. Not sure if this will ever happen because I DRIVE my car and have never been soft on it.

I am not sure if cleaning my throttle body or changing my plugs (50k on them) will help me attain any better mileage.... what do you guys think?

 

I'm not sure what cleaning the throttle body will do for fuel economy and providing your plugs are OEM platinum you should still have some life in them

Try adding a bottle of Chevron Techron say 250 miles before your next oil change and see what that does. You might also want to consider Seafoam through the brake booster hose.

What's killing you is the city driving. Your mileage isn't too bad on the highway.

Also check your tire pressure and over-inflate them slightly (say 35 PSI).

 

The max says premuim in the fuel door. And the common answer is running anything higher then recommened will not help while running less then what is specified will. So isn't anything below premuim bad? Also running premium will let you further advance timeing if I am correct which breings with it better gas mileage and performance?

 

The timing can be advanced on a 5th Gen but not a 4th Gen. Higher octane gasoline is required with the advanced timing, ie. premium.

 

That's because you have to doante.

As for the thread .. IMHO I think keeping your car in tip top condition has everything to do with gas mileage. I drive mine like a maniac most of the time (70/30) And still get 27 MPG.

 

You're technically incorrect. 4th gen timing can be advanced however, you will have to use an SMT unit or upgrade your ECU through JWT or Technosquare. The 5th gen advance that we can't do is via Consult II as our ECUs "forget" the setting when the car is turned off.

 

My bad! I was referring to the Consult II approach without being explicit enough.

 

I thought the engine advances its timiing on its own? A remeber seeing a thread on this that someone had hooked up a palm pilot and showed some of the results. Maybe in one of the stickies, let me try to find it.

 

i'll try that one definetly

 

fuel filter, spark plugs, air filter, wiring, just do the works...I just did...not that it mattered because the cars not running. LMAO