Tire pressure
Well... well... i'll be dammmn... after averaging about 26-28 mpg.. for 4 tanks.. i pumped my tired up and did not top off and guess what? i'm at 240 with about 1/4 tank left.. the needle during the last half of the tank isn't going down as fast anymore.. before it shot down very fast.. but now it's going down really slow...
i hope to break 300 miles on this tank before the red light comes on..
normally about 1 gallon left.. that will give me an average of about 33mpg.. i'll be soooo happy.. it seems like once i hit 1k it started drinking less gas.. i'll report back when i hit red light.. it looks promising.. i'll take 33mpg anyday!!!
i hope to break 300 miles on this tank before the red light comes on..
normally about 1 gallon left.. that will give me an average of about 33mpg.. i'll be soooo happy.. it seems like once i hit 1k it started drinking less gas.. i'll report back when i hit red light.. it looks promising.. i'll take 33mpg anyday!!!
overinflation
Just a word of caution about running your tires at 45+ psi. That is a lot of overinflation and you will have uneven tire wear (heavy wear in the center of the tread) as well as handling/braking issues, a harsh ride, and increased potential for road-hazard damage. I can't believe that you are saving enough on fuel to offset the cost of shorter tire life and increased wear on suspension parts. I run mine in the mid 30's, FWIW.
I haven't checked my OEM tire pressure until today (Fit Sport OEM wheels/tires). I saw the car get PDI'd...I basically bought it the day it came off the truck. Well, I found out today my tire pressures were 32 psi all the way around. Since max pressure is 40 psi, I'm having a feeling that's affected my gas mileage. Has anyone else played with the tire pressures and noticed any variations in mpg? I do mixed city/highway with the majority being city and I'm getting mid 20's.
I mounted up a set of 14" Civic steel wheels with 185/65/14 tires. I set all the tires to max 35 psi pressure. I'll post more mpg results after I fill up next and have a chance to observe.
I mounted up a set of 14" Civic steel wheels with 185/65/14 tires. I set all the tires to max 35 psi pressure. I'll post more mpg results after I fill up next and have a chance to observe.
i hate to say this but what is on the door for air psi is more for ride and safty than mpg just to give you an example the ford exploders they said 26 psi for the tires and had blow outs because of it and firestone took most of the blame just dont go over the max psi on the side wall and just to be safe at lest 2psi under it watch you tire wear see how they are wearing aligments will cut mpg as well as tire psi and tire rotation every 6000 miles will make you tires last longer if you want to know how i know i have been a tech for 13 years and i run a fleet shop and have save the company lots in gas
I know, nag nag nag! But just want to make sure you figure in the ratio difference (easy enough). It'll be interesting anyway!
???
Your dealer has never taken a physics class, huh?
Or perhaps they're trying to make a quick buck...The pressure of a gas changes based on temperature... Charles' Law
Don't fall for this bologna!!! Perhaps Nitrogen gas in tires has other benefits, but ALL GASES change in volume (therefore, pressure if confined to a set size space) based on temperature - so no pressure change due to temperature is NOT one of the benefits.
Sorry if someone already addressed this one - but that's just junk science right there.
Last edited by AppleMac*Fit; Oct 27, 2007 at 04:36 PM.
I think the big deal with the N2 fill is the lack of moisture, not so much the expansion rate of the gas. You might be shocked to see how much liquid water comes out of most commercial air hoses... Most of what I've read says that it's not really necessary for consumer automotive use, although I guess it's been used by racing teams for years. If they can tell the difference in 0.5psi change, it might be just the ticket for them. I certainly can't.
As soon as I could, I upped my tire pressure from the 32+/- it was delivered with to 38psi. I figure it's better for the short sidewalls with the roads around here, and the decrease in rolling resistance can't hurt. I keep our Pilot's tires at 36, so it's not really that high of a pressure. More than that I'm not really comfortable with except on the autoX course, as I know the pressure in our Pilot's tires really increases on long road trips. I saw over 4psi increase on our last spring break trip to CO on a cool day - not something I'd want to do on a hot day.
As soon as I could, I upped my tire pressure from the 32+/- it was delivered with to 38psi. I figure it's better for the short sidewalls with the roads around here, and the decrease in rolling resistance can't hurt. I keep our Pilot's tires at 36, so it's not really that high of a pressure. More than that I'm not really comfortable with except on the autoX course, as I know the pressure in our Pilot's tires really increases on long road trips. I saw over 4psi increase on our last spring break trip to CO on a cool day - not something I'd want to do on a hot day.
You will not know real gas mileage until you have 15,000 miles on the engine because that is how long it takes to be fully broken in.
Make sure to keep using 5W-20 oil (be sure your dealer isn't just putting 5W-30 in his bulk oil drum and using that in every car that comes in for maintenance). Of course beyond driving habits, proper tire inflation is the biggest impact on gas mileage.
Everybody should have a WalMart bicycle pump and digital air pressure guage and check their tire pressure once a week.
PS - if you consistently lose 2 or 3 pounds of pressure from the same tire every week, you've got a nail in that tire. Repair is to take the tire off the rim, plug the leak and put a patch on the inside. Hand torque the lug nuts when replacing the wheel. Everybody should have their own 1/2" torque wrench as well to hand torque after the tire shop gets done
Make sure to keep using 5W-20 oil (be sure your dealer isn't just putting 5W-30 in his bulk oil drum and using that in every car that comes in for maintenance). Of course beyond driving habits, proper tire inflation is the biggest impact on gas mileage.
Everybody should have a WalMart bicycle pump and digital air pressure guage and check their tire pressure once a week.
PS - if you consistently lose 2 or 3 pounds of pressure from the same tire every week, you've got a nail in that tire. Repair is to take the tire off the rim, plug the leak and put a patch on the inside. Hand torque the lug nuts when replacing the wheel. Everybody should have their own 1/2" torque wrench as well to hand torque after the tire shop gets done

Tips to improve your Gas Mileage
On a bike, where the tire pressure is much higher around 55-80psi, it makes a big difference. Trust me, I know. You can feel it. You actually have to pedal downhill if a bike is at 30psi. Plus,the higher pressure of bikes means it leaks more.
I have run 44 psi for 7 years on the Insight now approaching 200,000 miles and on my many CRX's and never had any problem at all. No flats, blowouts, uneven wear, loss of road adhesion, or suspension damage. the ride is a little rougher yes, but the cars just seem to roll far better and the difference in gas mileage is large. The Potenza's on the Insight and the Dunlops on the Fit are both spec'd at 44 max on the tirewall. These I am sure are conservative, or tire companies would be getting sued if failures did occur.
i hate to say this but what is on the door for air psi is more for ride and safty than mpg just to give you an example the ford exploders they said 26 psi for the tires and had blow outs because of it and firestone took most of the blame just dont go over the max psi on the side wall and just to be safe at lest 2psi under it watch you tire wear see how they are wearing aligments will cut mpg as well as tire psi and tire rotation every 6000 miles will make you tires last longer if you want to know how i know i have been a tech for 13 years and i run a fleet shop and have save the company lots in gas
what is more important?
ride
and safetyor
a tad better mpg?

ps: addressing the 26psi for the ford. my ford econo van was 35-36. 26 must of been a mistake as thats makes no sense
anyone driving a fit with over 38 psi is asking for trouble
Last edited by FIT410S; Jul 9, 2010 at 05:11 AM.



