30 messages,
Last post on May 12, 2010 at 2:22 PM
You are in the
Nissan 350Z/370Z Forum.
What is this discussion about?
Nissan 350Z, Fuel Efficiency (MPG), Coupe, Hatchback
Mar 03, 2008 (10:19 am)
1 oz per 20 gal is very low parts per million yet
there is no need for acetone less you want a temporary hp boost then add the 4 oz to the tank full.
For best mpg, no acetone is needed.
1. Disconnect the vapor canister by bypassing it. There are three hoses on the canister, one vents for fueling, connects to a solenoid and the other two connect close to each other on the vapor canister. Remove these two and connect them together. Put the heat shield back on after making this modification.
2. Disconnect the two wire plug from the evaporative solenoid on the engine(single throttle body mdls) located just to the passenger side of the throttle body assy.
3. Connect new wires from one side of the solenoid connect to ground, the other side to a switch (two pole, on off) mounted under the dash connect the other side of the switch to the cold side of the accessory cigar lighter fuse then reinstall the fuse.
side effects:
1. Leave engine running while fueling with switch on allowing tank vapor to be sucked through the engine in order to allow fuel to enter the tank, normally the third vent on the vapor canister would open(solenoid via pressure sensor) and allow tank to be filled venting vapor outside above the rear diff./axle assy.
2. Leave switch off during wild driving, sharp turns will allow raw fuel to suck through the vapor system reducing mpg.
3. Don't fill tank over half full to prevent fuel from splashing onto the top of the tank which will allow raw fuel to suck through the vapor system reducing mpg.
Results:
55 degree outside temp
72mph rewards 31 mpg
30 degree outside temp
72 mph rewards 28 mpg
70 degree outside temp
72 mph rewards 34 mpg
70 degree outside temp
62 mph rewards a phenomenal 42 mpg
Try it yourself. All of this is easily reversible to put the car back factory.
The evaporative computer is a separate computer from the cars main computer. To reset the evaporative which will turn off the check engine light after you put everything back to factory you must disconnect the battery for 24 hrs. Odd reset procedure unlike the cars main computer which is reset with a series of steps or simply removing the battery cables momentarily. As info. Love my homemade hybrid z...
oh. One other thing, More hp comes from adding vapor, the o2 sensor is backing off fuel during normal driving due to the excess fuel it smells due to excess vapor causing good mpg but when you accelerate hard the o2 sensor is not used and computer dumps max fuel meaning you now have max fuel plus vapor off the tank. Full tank of fuel spills fuel into the vapor line which also gives more power.
Jul 18, 2008 (7:33 am)
I drive my 350Z about 100 miles per day, 90% of which is interstate. I was getting 23 mpg average. I have always driven 75 on the interstate, and I like to accelerate quickly from stoplights. However, a couple of weeks ago, I computed how much money my wife and I are spending each month on gasoline. I was spending nearly $500 per month in my car, and she was spending nearly $700 per month in hers (Denali). She just bought a 4 cylinder Camry, and we are going to drive the Denali very sparingly.
I studied the hypermiling websites to try to figure out how to get better gas mileage. I have slowed to an average of 55 mph. I do pulse and glide with the engine on (accelerate to 60, coast down to 50, then repeat). I also have started accelerating more slowly (2,000 rpm instead of 4,000). I coast to stoplights instead of rushing to them and slamming on my brakes. I turn my engine off if I know it is going to be a long stoplight (over 30 seconds). I do not draft behind semi's or drive with the engine off while coasting at highway speeds because I am afraid of getting decapitated by a tire if the semi has a blowout and because I am afraid of losing control without power steering and brakes.
I reset the mpg gauge, and my new average for combined city/highway miles is 31.9 mpg. I also tested the highway mileage by resetting it when I got on the interstate and then looking at it when I exit. If I pulse and glide, I average 36 mpg on the interstate. If I set the cruise to 55, I average 33 mpg on the interstate. The city mileage still sucks (9 to 18 mpg), but luckily, I don't have much city driving. I calculated my mileage manually after my first full tank since driving this way, and I got 30.4 mpg. I filled up at 492 miles, and I could have gone well over 500 miles (maybe 600), but I didn't want to push it, and I wanted to fill up with the same pump.
I don't know if I will be able to keep driving this way. I've always been a lead foot, but it's nice to know you can get decent mileage if you try. Also, I still have the power there when I want to accelerate. Maybe I just don't have to drive that way all the time...
#23 of 30 Averaging 19mpg 50city/50highway fairly short runs of 10-15 miles.
by car_love
Apr 07, 2010 (10:53 am)
I'm driving a 2005 350z Touring - I commute about 15 minutes to work 50/50 highway/city. I don't gun it, shift at about 2600 RPMs and will shift to 5th or 6th if coasting/cruising real slow on city streets (around 40mph-50mph). I get about 19mpg by doing the check miles, record number of gallons to fill, then rinse and repeat... after two fill ups from half tank. Doing the math, I get exactly 19.20 MPG. I imagine if I drive on the highway a lot longer, it'll improve by about 5mpg or so.
#24 of 30 Re: Averaging 19mpg 50city/50highway fairly short runs of 10-15 miles. [car_love]
by biancar
Apr 07, 2010 (11:10 am)
That's about what I get too. Definitely the more highway miles, the better the mileage per gallon. This is a car that likes to run, not poke around in the city.
#25 of 30 Re: Averaging 19mpg 50city/50highway fairly short runs of 10-15 miles. [biancar]
by car_love
Apr 07, 2010 (11:37 am)
For sure, I'm learning that now. I do simply LOVE driving the car. Haven't had this much fun in years.
#26 of 30 Re: Averaging 19mpg 50city/50highway fairly short runs of 10-15 miles. [car_love]
by biancar
Apr 07, 2010 (1:58 pm)
Exactly my thought when I bought it! Mine is a Redline Touring Roadster, 2005, bought in April, 2006, exactly 4 years ago. (It had arrived at the dealer in the late fall of 2005 - not a great time to sell convertibles. So I got a great deal on it.) Love, love, love it.
I track the mpg quite often. On a long highway trip with very little city traffic, I'll get between 25 and 26 mpg. If it's mostly putzing around town, doing errands, stuck in traffic, lots of stops and starts, it's around 19. Both those numbers are comparable to our outgoing 2000 Maxima GLE (being traded in tomorrow for a new car.) I think that's pretty good that a sports-oriented roadster, driven most of the time with top down, in a reasonably "spirited" way, gets almost identical mileage to the family sedan.
#27 of 30 Re: Averaging 19mpg 50city/50highway fairly short runs of 10-15 miles. [car_love]
by qbrozen
Apr 08, 2010 (11:19 am)
FYI.
I once read that the best way to get good mileage out of a stick is "foot to the floor and short shift." Using this method, I used to get 25mpg with my 6-speed Touring Z with about 30-40% around town driving.
#28 of 30 gas mileage update
by car_love
Apr 13, 2010 (10:16 am)
Here's my fill up report today:
167 miles on 7.938 Gallons = 21.03 mpg 50city//50highway. I'm actually pretty happy with that. I got bought the car with no gas in it and have a feeling it was regular, think I just had to clear out the cobwebs. Excellent car! Loved it in the canyons this weekend.
#29 of 30 Re: gas mileage update [car_love]
by biancar
Apr 13, 2010 (11:41 am)
Glad you're having fun!
21 mpg isn't too terrible. The more highway miles, the better; the more in-town miles, the worse. 21 is a decent average.
#30 of 30 Re: gas mileage update [biancar]
by car_love
May 12, 2010 (2:22 pm)
thanks, love the car, great fun. just getting the little gremlins out that the previous owner chose to ignore LOL like a bad clutch master cylinder.