Finally, got 30 MPG
06-17-2011, 07:58 AM
#1
Finally, got 30 MPG
While I know my Maxima isn't the first to break the 30 MPG mark and is most likely not the last to do so, it has been a goal for me to see if my car could really hit the 30 MPG mark since I got it a year and 2 months ago.
I made a trip from Philadelphia to Virginia Beach going down I95 to DE-1 to US-13 and then reverse. The speed ranged from 35 MPH to 70 MPH. It is much less stop and go traffic like you would experience in the city but US-13 had stop lights that caused me not to be able to avoid coming to a complete stop.
The car carried 4 adults and some luggage and a full size spare. No weight reduction, stock rims. I would say the car weighed about 700 +/- 50 lbs over stock. Only modification to engine is a home made Hybrid SRI. KYB GR2 struts and stock springs.
I did make use of the cruise control and the car is a 02 6MT SE w/ Leather Interior. The SES light was on the whole time for bad cats. I didn't beat on it on the drive home after a fresh fill up of Shell V-Power.
I drove 252.6 miles.
The next fill-up at that point took about 8.219 gallons of gas.
The entire time the car's MPG was saying about 36.4 to 36.7.
My total miles driven plus DTE reached as high as 594.
Final calculated MPG was 252.6/8.219 (less than half a tank of gas) was 30.73366. Close to 31 MPG.
Man I love that we can get such amazing mileage out of these cars with a 3.5 V6 from a decade ago.
I made a trip from Philadelphia to Virginia Beach going down I95 to DE-1 to US-13 and then reverse. The speed ranged from 35 MPH to 70 MPH. It is much less stop and go traffic like you would experience in the city but US-13 had stop lights that caused me not to be able to avoid coming to a complete stop.
The car carried 4 adults and some luggage and a full size spare. No weight reduction, stock rims. I would say the car weighed about 700 +/- 50 lbs over stock. Only modification to engine is a home made Hybrid SRI. KYB GR2 struts and stock springs.
I did make use of the cruise control and the car is a 02 6MT SE w/ Leather Interior. The SES light was on the whole time for bad cats. I didn't beat on it on the drive home after a fresh fill up of Shell V-Power.
I drove 252.6 miles.
The next fill-up at that point took about 8.219 gallons of gas.
The entire time the car's MPG was saying about 36.4 to 36.7.
My total miles driven plus DTE reached as high as 594.
Final calculated MPG was 252.6/8.219 (less than half a tank of gas) was 30.73366. Close to 31 MPG.
Man I love that we can get such amazing mileage out of these cars with a 3.5 V6 from a decade ago.
06-17-2011, 08:48 AM
#4
The dash works on IPW. Add larger injectors, and the ECU thinks ZOMGZ! I need to take more fuel out, so you will get even better dash readings.
Dash readings come from IPW, not MAF. I've been -17% on MAF and no difference on dash.
Coasting just after the Z33 injector install... cannot be in N because then the ECU will add fuel to be @ 14.7 ... coasting in a drive gear, my WB reads off the carts (19.0):
Dash readings come from IPW, not MAF. I've been -17% on MAF and no difference on dash.
Coasting just after the Z33 injector install... cannot be in N because then the ECU will add fuel to be @ 14.7 ... coasting in a drive gear, my WB reads off the carts (19.0):
06-17-2011, 10:10 AM
#5
06-17-2011, 10:11 AM
#6
.best I got was 30.4x in my 95 on the highway, same trip, same avg. MPH.
06-17-2011, 11:33 AM
#7
I haven't had the opportunity to do a full tank of highway driving in the 4 years that I've owned my "pathetic" 4at. With that being said, I've gotten as high as 28 from mixed driving. Our cars tend to do better in the 70-80 mph range than in the 50-60 mph range. At least, that had been my experience.
06-17-2011, 11:33 AM
#8
06-17-2011, 11:56 AM
#11
06-17-2011, 12:10 PM
#12
06-17-2011, 12:11 PM
#13
06-17-2011, 12:20 PM
#14
Pretty sure they didn't change anything since 99. The 00 was a B suffix in the code, and it denotes the FD change to accommodate the larger diameter tires.
The V denotes VLSD. They're all the same since 97, possibly even 95 IIRC.
The V denotes VLSD. They're all the same since 97, possibly even 95 IIRC.
06-17-2011, 01:35 PM
#16
When I spoke with Jeff at Maxtuning he informed me Nissan did several things to beef up the 02+ transmissions. He referred me to Wayne who actually does all of their transmission work and he said there's a lot of small differences between the 5th and 5.5 gen transmissions. I'm going to continue to dig a little deeper with some additional sources I have.
06-17-2011, 01:38 PM
#17
When I spoke with Jeff at Maxtuning he informed me Nissan did several things to beef up the 02+ transmissions. He referred me to Wayne who actually does all of their transmission work and he said there's a lot of small differences between the 5th and 5.5 gen transmissions. I'm going to continue to dig a little deeper with some additional sources I have.
Probably a combination of age and torque.
06-17-2011, 01:43 PM
#18
Senior Member
Join Date: Oct 2005
Location: Pullman, WA
Posts: 486
What is typical for the 5.0s/5MTs? I get about 24 city and 30 highway (calculated miles driven divided by gallons to fill). IMO this was always higher than what I generally see so I haven't put much effort into improving my mpgs.
06-17-2011, 02:04 PM
#20
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Join Date: Oct 2005
Location: Pullman, WA
Posts: 486
06-17-2011, 02:08 PM
#21
06-17-2011, 02:08 PM
#22
Now I'm starting to wonder what I would get if I didn't have the AC on the whole way and shaved off 500-600 pounds. Planning on replacing my bad cats with headers in the future and will need to install my plenum spacers and possibly a BOP.
06-17-2011, 02:09 PM
#23
06-17-2011, 02:11 PM
#24
Senior Member
Join Date: Oct 2005
Location: Pullman, WA
Posts: 486
Also from my searching it seems like you won't be able to get much more than 200 pounds off and at that point you won't be able to take passengers any more
Also as part of your weight removal you will be taking out the compressor so you won't have to worry about AC afterwards lol
Last edited by ffcbairn; 06-17-2011 at 02:15 PM.
06-17-2011, 02:27 PM
#27
06-17-2011, 06:30 PM
#29
06-17-2011, 08:53 PM
#31
Senior Member
Join Date: Sep 2008
Location: SoCal
Posts: 427
S**t...i'm in the 17/18 range b/c i've got 1 bad precat 
with an auto. Man, what I would do to swap all my stuff to a 6MT!! That's it...i'm pull'n my y-pipe right now(at least start that phase tonight)...
did it...and now it's time to fab up my own 3" y-pipe into 3" cat+catback....then wrap it in heat shield
with an auto. Man, what I would do to swap all my stuff to a 6MT!! That's it...i'm pull'n my y-pipe right now(at least start that phase tonight)...did it...and now it's time to fab up my own 3" y-pipe into 3" cat+catback....then wrap it in heat shield
Last edited by 00Lightsout; 06-21-2011 at 01:31 AM.
06-17-2011, 09:25 PM
#32
Join Date: Jan 2011
Posts: 17
I don't really think that 30mpg for this is a big deal. Before I got my I35 i had a 95 Trans am with a 5.7L V8 and 4spd Auto. On highway trips back and forth from school I would regularly see 30-31 mpg. And i would have the car stuffed to the roof with stuff. Probably because the rear end ratio was low enough that the engine would be turning at 16-1700 rpm at 70mph. Boy do I miss that cruiser.
06-17-2011, 09:55 PM
#33
Hey my 4AT does 31 mpg on the highway and that's calculated true mpg not some estimated dashboard read which is always innacurate. Too bad it only does 18 mpg in crappy Chicago city driving. I really found it weird when I was able to get 400+ to the tank with mixed driving mostly on highway and out of Chicago (25mpg), and driving in Chicago I only get 18 mpg. That's a big difference!
06-17-2011, 09:59 PM
#34
06-17-2011, 10:28 PM
#35
I don't really think that 30mpg for this is a big deal. Before I got my I35 i had a 95 Trans am with a 5.7L V8 and 4spd Auto. On highway trips back and forth from school I would regularly see 30-31 mpg. And i would have the car stuffed to the roof with stuff. Probably because the rear end ratio was low enough that the engine would be turning at 16-1700 rpm at 70mph. Boy do I miss that cruiser.
That's not to say I haven't seen over 35 mpg from both of those cars, but I like to see if the car I've switched to is capable of breaking that 30 mpg barrier. I don't do regular all highway trips and for this roadtrip, I was excited to see if it was capable of doing so.
06-18-2011, 04:35 PM
#36
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Join Date: Mar 2001
Location: Manhattan Beach, Ca / Dallas, Tx
Posts: 3,751
Absolutely, as the 5spd auto in the 6th gen is crap.....Failure after failure/issue after issue. They have tons of failure threads and a class action Lawsuit thread about it in the 6th gen forum. As you posted further down, there are several internal differences that strengthened the 02/03 and early 04 SL Maxima 4spd auto from the older ones to handle the additional torque and power. Nissan also stated back then that they beefed it up quite a bit for the 02 Max.
06-20-2011, 10:37 AM
#37
Hey my 4AT does 31 mpg on the highway and that's calculated true mpg not some estimated dashboard read which is always innacurate. Too bad it only does 18 mpg in crappy Chicago city driving. I really found it weird when I was able to get 400+ to the tank with mixed driving mostly on highway and out of Chicago (25mpg), and driving in Chicago I only get 18 mpg. That's a big difference!
7AT from the new Infiniti G.
I still say MT > AT no matter how many gears.
06-20-2011, 10:57 AM
#38
Senior Member
Join Date: Aug 2007
Location: Delafield, WI
Posts: 486
I've been changing my driving habits lately to improve fuel economy. www.cleanmpg.com has a lot of tips to do so. Some "hypermiling" tricks are easy to implement, and some may be a bit extreme for some. A simple highway trick I found is instead of using cruise control you drive with load. That means keeping the engine at a constant load, rather than maintaining a constant speeed. For instance...Approaching a hill driving in cc the car will maintain the speed by increasing engine load. That wastes a bit more gas. It's better to keep steady pressure on the gas pedal and allow the car to bleed a little speed going up a hill and regain the speed going down the hill. This can be monitored with those that have a VAFC/SAFC by looking at the % of throttle. I actually purchased an Ultra-Gauge that plugs into my OBD2 port allowing me to have various gauges to watch including instant MPG and Engine load %.
06-20-2011, 02:24 PM
#39
^ good point. When It got to hilly areas, I took it off of cruise control. I'd hold steady for uphills and throw it in neutral for downhills depending on how steep it was. Cruise control is useful, but when driving on roads that aren't flat, it's not necessarily the best way to obtain higher fuel economy.
06-21-2011, 01:04 AM
#40
^ good point. When It got to hilly areas, I took it off of cruise control. I'd hold steady for uphills and throw it in neutral for downhills depending on how steep it was. Cruise control is useful, but when driving on roads that aren't flat, it's not necessarily the best way to obtain higher fuel economy.
Modern cars will cut fuel to the cylinders when you are a little above idle (~1000+ rpm) and coasting in gear (i.e. throttle closed). Shifting to neutral thus uses more fuel...