has your m.p.g. gone UP or DOWN since 17" rims? what draw backs if any have you experianced?

 

It would go up if they are heavier than stocks, but if they are very light than you should see the same or slightly better thans stock.

 

yes heavier rotating mass = less m.p.g., but i'd like to know actual real world figures. any of you take acual readings on before and after installing 17's, what are they?

 

My gas milage went up only because I drive slower to avoid denting them up in pot holes or curb rashing them.

 

/\/\/\ me 2...my gas mileage stayed the same....prolly a lil better cause i don't drive with a heavy foot anymore...and i'm on 18's.

 

2002 Max 17's" with very little change in mileage

 

nothing noticeable. i got about 350 per tank on stock 15's.. i get the same now with 17's.. but i think the offset is off by about 2 percent according some some tire rotation calcuator. so if my speedo says 100. im readyy doing 98. its marginal but makes a difference if your a tree hugger.

 

My stock 15's(honeycomb) weigh 39.5 lbs/corner, and my lightweight 17" weigh 37.5/corner.

I went from stock 17" wheels (2003) and went to lightweight 17" wheels, and saw an increase of ~ 8-10% w/ the LW wheels.

Then there's the rotating mas deal, so try some LW wheels if you can.

 

I went down, but reading some of your posts I guess I'm in good shape with 350. But before I was getting 400+.

 

while there is a direct affect on MPG involved when installing larger rims, there is also an indirect one as well....if you have been driving on 15s or 16s for a while, you will be used to a certain level of acceleration, as measured by the Gs you're used to experiencing when accelerating. Now, slap on larger rims (I'm assuming you're not putting on larger, super-duper, light-as-styrofoam racing wheels but rather ones that weigh more than those you are replacing) and you're going to experience a decrease in acceleration. SO what do we do in such a case? We tend to mash down on the gas pedal that much harder in order to compensate, to get that acceleration back. I know not everyone does that, but the psyche is relevant and undoubtedly present. I bring this up because this affects MPG and thus, will make the responses in this thread highly variable.

 

/\/\ damn you were getting 400mpg? shiez...i'm only topping out at 330-350...what type of gase are you using? driving habbits? any engine modifications?

 

i got a the 350z 17s about a month ago and mine has remained the same

 

when you put bigger diameter wheels on your car it increases the rotational diameter which, if you dont recalibrate your ecu (if its possible) to the new wheel size it will effect your speedometer making it say you're going slower and it will effect your gas milage making it say you're getting worse gas milage because the computer cant compensate for the change in wheel size.

 

It all depends on the weight of the rims. If its heavier then the stock, like chromes, Expect poor gas mileage.

 

Not to mention that most times your ride quality will suffer with heavier rims.

 

I dont think we can recalibrate our VSS signal for the speedo. I do see what you're saying, but what you're saying would happen on an extreme of larger wheels, like 22s. As long as the OVERALL DIAMETER of the wheel/ tire combo is the same, it doesnt matter at all if you go from 15" rims to 18", given that you have the properly sized tire sidewall for it. If the tire covers the same distance in one rotation, with 15s or 18s, the speedo will not be off. Thats where the whole +1/+2/+3 rim and tire proer sizing come into play. I have 17" wrapped with 235/45-17s and my speedo is right on mark.

Anyways, stock saw blades are w/e they weigh, I then moved to Z32 wheels (16x7.5) that weigh 16.0 lb, and now Im on Borbet type E (17x8) that weigh 23lbs.... my milage has not changed. Its my driving habbits that are eating up my gas

 

all wrong think about it guys ur speedo is off so u cannot get true MPG
.....just thought i would throw that in there

 

my g35's ride so fresh n so cleannnnn....milage is great

 

Like i said, if the overall diameter of the wheel/tire combo is the same as that of the original wheels and tires, the speedo WILL NOT be off.

 

Why would you throw misinformation around like that? You ask us to 'think' about it... Well, instead of thinking about it.

Read this 3-5 times, and then you'll know what we're talking about. Cannot get a much clearer representation than this.


What do your wheels/tire weigh total (per corner)?