6 gas saving myths (at least 2 surprised me)
#21
The tires have tread wear indicators on them. Now, I have not been riding at 50psi the entire life of the tire more like ~2000-1500 miles.
As far as holes, I know where the bad spots in the road and can dodge them, however, I am usually not driving fast enough to do any damage if I do hit the bad areas of the road that I encounter.
As far as holes, I know where the bad spots in the road and can dodge them, however, I am usually not driving fast enough to do any damage if I do hit the bad areas of the road that I encounter.
#22
Once you dig deep enough, temperature becomes a near-constant.
You dont really need to get very deep either. Here is a quote from an article I found on geothermal heating/cooling:
Here is the article.
You dont really need to get very deep either. Here is a quote from an article I found on geothermal heating/cooling:
Here is the article.
#23
The tires have tread wear indicators on them. Now, I have not been riding at 50psi the entire life of the tire more like ~2000-1500 miles.
As far as holes, I know where the bad spots in the road and can dodge them, however, I am usually not driving fast enough to do any damage if I do hit the bad areas of the road that I encounter.
As far as holes, I know where the bad spots in the road and can dodge them, however, I am usually not driving fast enough to do any damage if I do hit the bad areas of the road that I encounter.
For me I tend to check my pressure regularly mainly to ensure safety and catch problems early on; but also to maintain good mileage (I usually get about 40mpg on the highway despite all my modifications geared towards performance.... although I haven't had a chance to track how the new engine management system impacts that, but that is another story).
I know for you guys who participate in the cleanMPG site the mileage is almost a status symbol. But for folks on here that might be interested in getting good mileage and still maintain the full ability of the tires, I wonder what the compromise pressure would be?
Just a side note; something else came to my attention today about the high PSI. I would imagine that your suspension is going to take a beating. If you get more than a year or two out of your shocks before they start sagging I would be impressed. Maybe something like this; https://www.fitfreak.net/forums/fit-...tml#post312380
for the rears to extend the life?
Last edited by Sugarphreak; 05-18-2008 at 10:09 PM.
#24
I know when I had my psi at 40(because I was to chicken to rock the 50psi) I was having a hard time achieving 42mpg. When I inflated to 50 psi 45mpg was a piece of cake and my max mpg was 47.9mpg I believe. This was in my thread labeled Stock air filter vs. K&N air filter. I drove the speed limit, used cruise control and the A/C(only on the 2nd half the daily commute). With that said, I have not performed a test to isolate strictly psi but it was a constant and the only difference was the air filters and the obviously daily variables such as weather and traffic.
For now, I am stickin with 50psi. Though I am interested in whether or not it will prematurely wear out the tires, hell I don't even know how many miles these tires should last.
That brings me to another question:
Any one know of some good tires that would yield better mpg? I would imagine a lighter tire but I would like something that would last so that would obviously NOT be a sticky tire, since I am not a track star.
For now, I am stickin with 50psi. Though I am interested in whether or not it will prematurely wear out the tires, hell I don't even know how many miles these tires should last.
That brings me to another question:
Any one know of some good tires that would yield better mpg? I would imagine a lighter tire but I would like something that would last so that would obviously NOT be a sticky tire, since I am not a track star.
Last edited by pb and h; 05-18-2008 at 10:16 PM.
#25
I was running 32psi when I achieved 42mpg on the way to and 44mpg from on my vacation destination last year. So many factors though... I was already running variety of mods, I have a feeling the tire size was a big factor because with the slightly larger diameter I was keeping the RPM under the Vtec engagement at highway speeds.
If I were to take my best stab at it, you are looking for two things; First, the treadwear rating would have to high and second, I think you would probably be looking for a tire that has a consistent contact with the road along the center. Anything with interrupted tread lines is going to grab a bit of friction as it impacts.
Another thing you could look at is maybe width. You could run a 185 tire instead of a 195 to further reduce your friction.
Actually now that I am thinking about it, the tires I have would probably be a good candidate. There is no interrupted tread line and the wear rating I believe it better than other tires.
Continental - ContiSportContact 2
I really wish you guys would run 40psi though just in case something ever happens, the car really starts to loose it's abilities at anything more than that
If I were to take my best stab at it, you are looking for two things; First, the treadwear rating would have to high and second, I think you would probably be looking for a tire that has a consistent contact with the road along the center. Anything with interrupted tread lines is going to grab a bit of friction as it impacts.
Another thing you could look at is maybe width. You could run a 185 tire instead of a 195 to further reduce your friction.
Actually now that I am thinking about it, the tires I have would probably be a good candidate. There is no interrupted tread line and the wear rating I believe it better than other tires.
Continental - ContiSportContact 2
I really wish you guys would run 40psi though just in case something ever happens, the car really starts to loose it's abilities at anything more than that
#26
I know it's already been said many times here and in other threads but the driving habits in my experience have a profoundly bigger impact on mpg than anything else including tire pressure. I have bumped mine up a bit to 44. Even after warming then they are still within the craplop's max rating. I didn't notice any difference in mileage from that. The difference seems to me to come 97% from cutting speed, avoiding quick acceleration, buffering and coasting vs braking.
I know when I had my psi at 40(because I was to chicken to rock the 50psi) I was having a hard time achieving 42mpg. When I inflated to 50 psi 45mpg was a piece of cake and my max mpg was 47.9mpg I believe. This was in my thread labeled Stock air filter vs. K&N air filter. I drove the speed limit, used cruise control and the A/C(only on the 2nd half the daily commute). With that said, I have not performed a test to isolate strictly psi but it was a constant and the only difference was the air filters and the obviously daily variables such as weather and traffic.
#28
Pressure would be for the max axle loads, should be in your owners manual.
I already mentioned this, but generally the max PSI is determined by the tire and has nothing to do with the car. The tire will have it printed on the side somewhere for safety reasons.
I already mentioned this, but generally the max PSI is determined by the tire and has nothing to do with the car. The tire will have it printed on the side somewhere for safety reasons.
#29
#30
I see what you are saying, but still the max pressure is going to be dependent on the tire. The tire will be rated for a certain load (which I doubt the Fit will exceed even with over weight axles loads), if you exceed that load then you compromise the tire and it basically is at risk of a premature blow out.
As long as you don't exceed the load spec for the tire you can inflate up to the max PSI written on the side safely. I believe the lowest rating you can have is 50psi, people inflating tires over that sidewall marking are at serious risk of having it blow up in their face!
Now, that doesn't mean running at the max PSI is safe, your traction becomes compromised because without the proper amount of weight on the tires it will have a tendency to bulge out along the bottom (which is what the hypermilers are taking advantage of, less surface area means less friction and increased mileage)
You may be correct about the recommended Honda PSI being low. They may have adjusted that PSI to suit an unloaded car to maximize the traction as more of a safety factor. However officially speaking, that is the pressure that should accommodate the max axle loads. I would say that if you constantly run with more weight in the vehicle it wouldn't hurt to use 3 or 4 more lbs of pressure to ensure you are getting the right mix of traction and economy.
As long as you don't exceed the load spec for the tire you can inflate up to the max PSI written on the side safely. I believe the lowest rating you can have is 50psi, people inflating tires over that sidewall marking are at serious risk of having it blow up in their face!
Now, that doesn't mean running at the max PSI is safe, your traction becomes compromised because without the proper amount of weight on the tires it will have a tendency to bulge out along the bottom (which is what the hypermilers are taking advantage of, less surface area means less friction and increased mileage)
You may be correct about the recommended Honda PSI being low. They may have adjusted that PSI to suit an unloaded car to maximize the traction as more of a safety factor. However officially speaking, that is the pressure that should accommodate the max axle loads. I would say that if you constantly run with more weight in the vehicle it wouldn't hurt to use 3 or 4 more lbs of pressure to ensure you are getting the right mix of traction and economy.
Last edited by Sugarphreak; 05-19-2008 at 05:35 PM.
#31
I have no chips in this pissing match, but will offer this fact. The 2008 Sport Dunlap tires say 51psi Max on the tire.
If you fill them to 50 at room temp, I assure you they will be greater the 51 after driving in warm to hot weather. No idea how warm they get in cold weather.
I live in South Fla and the roads get very hot here. Also the shell aggreget makes them get even hotter from extra friction. When I 1st started looking at this for my car in Feb, I experimented some. I posted the results on this site for all to read. I used a IR thermal gun and measured mine after driving for 30 min. Trust me, they get hot. The front a lot more than the rears for obvious reasons. Anyway, what I found is 45psi is the most I want at room temp to leave room for the expected and verified pressure increase at operating temp.
I doubt anyone on here knows how much over eng these Dunlap's are so I'm treating 51psi as it says max. Sugest you do as well
Now carry on.
If you fill them to 50 at room temp, I assure you they will be greater the 51 after driving in warm to hot weather. No idea how warm they get in cold weather.
I live in South Fla and the roads get very hot here. Also the shell aggreget makes them get even hotter from extra friction. When I 1st started looking at this for my car in Feb, I experimented some. I posted the results on this site for all to read. I used a IR thermal gun and measured mine after driving for 30 min. Trust me, they get hot. The front a lot more than the rears for obvious reasons. Anyway, what I found is 45psi is the most I want at room temp to leave room for the expected and verified pressure increase at operating temp.
I doubt anyone on here knows how much over eng these Dunlap's are so I'm treating 51psi as it says max. Sugest you do as well
Now carry on.
#32
For the people claiming significantly increased mpg with higher tire pressures: have you decreased the tire pressure and observed a decrease in mpg?
I ask because I've observed a significant increase in mpg for my fit over the first 8000 miles I've driven. Part of that has been my driving habits, but part of it could be "breaking in" the car. So perhaps the increase in MPG observed with increased tire pressure could be more from the Fit being "broken in" than the increased tire pressure. Or not.
I ask because I've observed a significant increase in mpg for my fit over the first 8000 miles I've driven. Part of that has been my driving habits, but part of it could be "breaking in" the car. So perhaps the increase in MPG observed with increased tire pressure could be more from the Fit being "broken in" than the increased tire pressure. Or not.
#33
I have no chips in this pissing match, but will offer this fact. The 2008 Sport Dunlap tires say 51psi Max on the tire.
If you fill them to 50 at room temp, I assure you they will be greater the 51 after driving in warm to hot weather. No idea how warm they get in cold weather.
I live in South Fla and the roads get very hot here. Also the shell aggreget makes them get even hotter from extra friction. When I 1st started looking at this for my car in Feb, I experimented some. I posted the results on this site for all to read. I used a IR thermal gun and measured mine after driving for 30 min. Trust me, they get hot. The front a lot more than the rears for obvious reasons. Anyway, what I found is 45psi is the most I want at room temp to leave room for the expected and verified pressure increase at operating temp.
I doubt anyone on here knows how much over eng these Dunlap's are so I'm treating 51psi as it says max. Sugest you do as well
Now carry on.
If you fill them to 50 at room temp, I assure you they will be greater the 51 after driving in warm to hot weather. No idea how warm they get in cold weather.
I live in South Fla and the roads get very hot here. Also the shell aggreget makes them get even hotter from extra friction. When I 1st started looking at this for my car in Feb, I experimented some. I posted the results on this site for all to read. I used a IR thermal gun and measured mine after driving for 30 min. Trust me, they get hot. The front a lot more than the rears for obvious reasons. Anyway, what I found is 45psi is the most I want at room temp to leave room for the expected and verified pressure increase at operating temp.
I doubt anyone on here knows how much over eng these Dunlap's are so I'm treating 51psi as it says max. Sugest you do as well
Now carry on.
I believe that the max tire rating is going to be cold PSI, there is a previous post to an article on Tirerack which talks about this.
With that said, 51 psi is way to freaking much!!!
For the people claiming significantly increased mpg with higher tire pressures: have you decreased the tire pressure and observed a decrease in mpg?
I ask because I've observed a significant increase in mpg for my fit over the first 8000 miles I've driven. Part of that has been my driving habits, but part of it could be "breaking in" the car. So perhaps the increase in MPG observed with increased tire pressure could be more from the Fit being "broken in" than the increased tire pressure. Or not.
I ask because I've observed a significant increase in mpg for my fit over the first 8000 miles I've driven. Part of that has been my driving habits, but part of it could be "breaking in" the car. So perhaps the increase in MPG observed with increased tire pressure could be more from the Fit being "broken in" than the increased tire pressure. Or not.
Last edited by Sugarphreak; 05-19-2008 at 11:29 PM.
#34
I see what you are saying, but still the max pressure is going to be dependent on the tire. The tire will be rated for a certain load (which I doubt the Fit will exceed even with over weight axles loads), if you exceed that load then you compromise the tire and it basically is at risk of a premature blow out.
As long as you don't exceed the load spec for the tire you can inflate up to the max PSI written on the side safely. I believe the lowest rating you can have is 50psi, people inflating tires over that sidewall marking are at serious risk of having it blow up in their face!
Now, that doesn't mean running at the max PSI is safe, your traction becomes compromised because without the proper amount of weight on the tires it will have a tendency to bulge out along the bottom (which is what the hypermilers are taking advantage of, less surface area means less friction and increased mileage)
You may be correct about the recommended Honda PSI being low. They may have adjusted that PSI to suit an unloaded car to maximize the traction as more of a safety factor. However officially speaking, that is the pressure that should accommodate the max axle loads. I would say that if you constantly run with more weight in the vehicle it wouldn't hurt to use 3 or 4 more lbs of pressure to ensure you are getting the right mix of traction and economy.
As long as you don't exceed the load spec for the tire you can inflate up to the max PSI written on the side safely. I believe the lowest rating you can have is 50psi, people inflating tires over that sidewall marking are at serious risk of having it blow up in their face!
Now, that doesn't mean running at the max PSI is safe, your traction becomes compromised because without the proper amount of weight on the tires it will have a tendency to bulge out along the bottom (which is what the hypermilers are taking advantage of, less surface area means less friction and increased mileage)
You may be correct about the recommended Honda PSI being low. They may have adjusted that PSI to suit an unloaded car to maximize the traction as more of a safety factor. However officially speaking, that is the pressure that should accommodate the max axle loads. I would say that if you constantly run with more weight in the vehicle it wouldn't hurt to use 3 or 4 more lbs of pressure to ensure you are getting the right mix of traction and economy.
My main gripe was the loss of traction in bumpy corners. Oklahoma roads are terrible - 40 psi really caused the car to lose its composure when the roads turned rough.
I promptly went back to 32 psi. I don't feel that any improvement in rolling resistance is worth the tradeoff in safety. My most recent tank came in at 40.4 mpg - that's good enough for me.
#35
#2. Change your air filter
Maintaining your car is important, but a clean air filter isn't going to save you any gas. Modern engines have computer sensors that automatically adjust the fuel-air mixture as an increasingly clogged air filter chokes off the engine's air supply.
While engine power will decrease slightly as the air filter becomes clogged, a lack of performance or an increase in fuel consumption will be negligible, Consumer Reports says.
Maintaining your car is important, but a clean air filter isn't going to save you any gas. Modern engines have computer sensors that automatically adjust the fuel-air mixture as an increasingly clogged air filter chokes off the engine's air supply.
While engine power will decrease slightly as the air filter becomes clogged, a lack of performance or an increase in fuel consumption will be negligible, Consumer Reports says.
#4. Pump up your tires
...
But you should never over-inflate your tires. They'll get you slightly better fuel economy because there will be less tread touching the road, reducing friction. But that means less grip for braking and turning. The added risk of a crash isn't worth the extra mile a gallon you might gain.
...
But you should never over-inflate your tires. They'll get you slightly better fuel economy because there will be less tread touching the road, reducing friction. But that means less grip for braking and turning. The added risk of a crash isn't worth the extra mile a gallon you might gain.
#6. Bolt-ons and pour-ins
Before you buy a device that's supposed to make your car more fuel-efficient or pour in an allegedly gas-saving additive, ask yourself this: Don't you think oil and car companies aren't doing everything they can to beat their competitors?
Before you buy a device that's supposed to make your car more fuel-efficient or pour in an allegedly gas-saving additive, ask yourself this: Don't you think oil and car companies aren't doing everything they can to beat their competitors?
#36
Yeah on the Premium thing, I use to have a 94 Prelude that said Premium only, but ran just fine with no low octane ping on Regular. I'm sure there was a slight drop in performance but I tried premium for a month and didn't notice any difference.
What surprises me is that link to the Top 8 most fuel efficient cars. 8 was the Yaris which was stated to get 32mpg...which is worse than a fit.
What surprises me is that link to the Top 8 most fuel efficient cars. 8 was the Yaris which was stated to get 32mpg...which is worse than a fit.
Last edited by Tofuik; 06-08-2008 at 07:51 PM.
#37
A dirty air filter becomes clogged with crud and can't pass as much air through. With a dirty air filter the engine can't breathe as well and it won't be able to make as much power. The ECU will compensate for the lower amount of air by adjusting the fuel accordingly, hence no loss of fuel economy -- just a loss of performance.
#38
It won't affect the oil. A dirty air filter does not let dirt in, it keeps air out.
A dirty air filter becomes clogged with crud and can't pass as much air through. With a dirty air filter the engine can't breathe as well and it won't be able to make as much power. The ECU will compensate for the lower amount of air by adjusting the fuel accordingly, hence no loss of fuel economy -- just a loss of performance.
A dirty air filter becomes clogged with crud and can't pass as much air through. With a dirty air filter the engine can't breathe as well and it won't be able to make as much power. The ECU will compensate for the lower amount of air by adjusting the fuel accordingly, hence no loss of fuel economy -- just a loss of performance.
#39
Fuel saving tips that just don't work - May. 13, 2008
The two that surprised me
#2) air filter affects mileage/performance (false)
#3) use premium fuel if the mfg suggests it (false)
The two that surprised me
#2) air filter affects mileage/performance (false)
#3) use premium fuel if the mfg suggests it (false)
Some manufacturers tell you to use premium because their ignition system can't handle low test gas and results in detonation. And often premium has higher energy components than low test in order to attain the needed octane rating. The higher the energy rating in btu per lb the better gas mileagre you will get, all other things equal. Is it worth more than 8 cents per gallon at 3/gal? I doubt it nowdays. I agree that you should use the lowest octane gas the manufacturer recommends.
#40
[
That brings me to another question:
Any one know of some good tires that would yield better mpg? I would imagine a lighter tire but I would like something that would last so that would obviously NOT be a sticky tire, since I am not a track star.[/quote]
Cavalier, sorry, cobalts, recently improved their mpg ratings by going to lower rolling resistance tires like the Prius uses. Unless you get a 'touring' Prius, which has regular tires and loses 2 mpg in the rating.
If you drive in the mountains on crooked roads the 'ergular' Prius is a handful. Some RV's will out corner you. You don't get low rolling resist for nothing. These guys running 50 psi should see the same reduction in cornering plus wearing the center of their tread. When the center gets down to 2/32" the outer grooves will be 10./32.
Anyway, if youre looking for low rolling resistance tires check the ones on Cobalts now.
That brings me to another question:
Any one know of some good tires that would yield better mpg? I would imagine a lighter tire but I would like something that would last so that would obviously NOT be a sticky tire, since I am not a track star.[/quote]
Cavalier, sorry, cobalts, recently improved their mpg ratings by going to lower rolling resistance tires like the Prius uses. Unless you get a 'touring' Prius, which has regular tires and loses 2 mpg in the rating.
If you drive in the mountains on crooked roads the 'ergular' Prius is a handful. Some RV's will out corner you. You don't get low rolling resist for nothing. These guys running 50 psi should see the same reduction in cornering plus wearing the center of their tread. When the center gets down to 2/32" the outer grooves will be 10./32.
Anyway, if youre looking for low rolling resistance tires check the ones on Cobalts now.