Proper Tire Pressure...
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i'm curious about wear as well. i've heard some owners putting them up to near 50 :shock: i'd be too afraid for that high
i put air in 'em a few months ago, i think just above 40. tested last week and they showed high 30's. the wierd thing is my ride feels rougher now :? might just be since we moved and they are different roads.
and i can never seem to get an accurate reading with 1 single gauge. i have to use 2 or 3 just to get an idea of what the pressure is. does anyone know of an accurate gauge?
i put air in 'em a few months ago, i think just above 40. tested last week and they showed high 30's. the wierd thing is my ride feels rougher now :? might just be since we moved and they are different roads.
and i can never seem to get an accurate reading with 1 single gauge. i have to use 2 or 3 just to get an idea of what the pressure is. does anyone know of an accurate gauge?
I've been using around 40 psi in the front and around 37 in the back, and I do notice a difference of 2 or 3 mpg if it drops down to the manufacturer suggested pressures or below. I might try something closer to 45 once we finally get to spring (if it ever happens - the Arctic stuff just won't go away this year!).
One thing to consider: at higher pressure levels, less surface area of the tire will be in contact with the ground. That means less friction between the tire and the road, which might sound good at first until you realize I mean reduced traction. My feeling has been to let the tires run closer to manufacturer specs while the snow and ice has been on the road (and pay the price in slightly worse MPG), but pump it up when the weather gets nice again.
One thing to consider: at higher pressure levels, less surface area of the tire will be in contact with the ground. That means less friction between the tire and the road, which might sound good at first until you realize I mean reduced traction. My feeling has been to let the tires run closer to manufacturer specs while the snow and ice has been on the road (and pay the price in slightly worse MPG), but pump it up when the weather gets nice again.
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618 Posts
Tire Pressure
The sidewall max tire pressure is a cold inflation pressure. For those worried about tire failure keep in mind that the tire pressure increases as the tire temperature increase. The temperature will increase due to the rolling resistance (In other words the faster you go the higher the temp). Also the rougher the road the more the temp will increase. I assume that the value stated was derived based on sumertime hot road temps, rough roads, and driven at the speed rating of the tire. If this is a correct assumption then the average driver will likely never reach the true max hot tire pressure. As a result I use a 50 psi pressure and feel safe for my driving which is mostly around 55 mph for max fuel economy. I will agree that the higher pressure will degrade cornering/braking on dry roads. But the higher pressure will help reduce hydroplaning on wet roads. Have fun,
The sidewall max tire pressure is a cold inflation pressure. For those worried about tire failure keep in mind that the tire pressure increases as the tire temperature increase. The temperature will increase due to the rolling resistance (In other words the faster you go the higher the temp). Also the rougher the road the more the temp will increase. I assume that the value stated was derived based on sumertime hot road temps, rough roads, and driven at the speed rating of the tire. If this is a correct assumption then the average driver will likely never reach the true max hot tire pressure. As a result I use a 50 psi pressure and feel safe for my driving which is mostly around 55 mph for max fuel economy. I will agree that the higher pressure will degrade cornering/braking on dry roads. But the higher pressure will help reduce hydroplaning on wet roads. Have fun,
Hello all just found the group again after MIZR and I have been out of link. I have run MIZR at 45psi since I got him (2000 5 spd) and I found that the tire wear wasnt to bad I got about 50000 miles out of original set and replaced them with the same tire. As for handling actually if you are semi aggressive the original tires don't handle so badly on dry pavement. I found at 45 psi I had a semi decent ride and best mileage.
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1,228 Posts
Blow 'em up to 50
I have always run my tires, on all my vehicles, past the sidewall recommendation, with the following results: better mileage, handling, better cargo-carrying capacity, and less "wondering" on crowned roads or running over trolley tracks (especially on odd-tracked cars like my old Citroen and the Insight). Using greater-than-sidewall presures (2-5 lbs over), I have never, in almost 40 years of driving, had a blow-out or weird handling or strange wear patterns (unless I tag a curb and throw the alignment out of whack). So far, no problems, and don't expect any. Now, let me throw something out there: Since my first front driver (a '66 MG 1100, which was like a bigger Mini), I have NEVER rotated tires. The front tires wear out as expected, and I buy a new pair and slap them on. The rear tires, however, (which, on a "puller," are only used to reduce friction by keeping the rear bumper off the road), have lasted me from a minimum of about twice the expected life to my grand champion, a set on a mid-'80s Subaru wagon that went a total of 132,000 miles... and I only changed them when the wear bars showed up. I'm not planning on rotating my Insight tires, just to see what happens... I expect to get better than 100,000 miles on the LRR rears, we'll see...
I have always run my tires, on all my vehicles, past the sidewall recommendation, with the following results: better mileage, handling, better cargo-carrying capacity, and less "wondering" on crowned roads or running over trolley tracks (especially on odd-tracked cars like my old Citroen and the Insight). Using greater-than-sidewall presures (2-5 lbs over), I have never, in almost 40 years of driving, had a blow-out or weird handling or strange wear patterns (unless I tag a curb and throw the alignment out of whack). So far, no problems, and don't expect any. Now, let me throw something out there: Since my first front driver (a '66 MG 1100, which was like a bigger Mini), I have NEVER rotated tires. The front tires wear out as expected, and I buy a new pair and slap them on. The rear tires, however, (which, on a "puller," are only used to reduce friction by keeping the rear bumper off the road), have lasted me from a minimum of about twice the expected life to my grand champion, a set on a mid-'80s Subaru wagon that went a total of 132,000 miles... and I only changed them when the wear bars showed up. I'm not planning on rotating my Insight tires, just to see what happens... I expect to get better than 100,000 miles on the LRR rears, we'll see...
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1,228 Posts
It's getting hot in here...
Man, we looooove San Diego. The whole SoCal area is a national treasure. One of our most memorable drives through your part of the world took us from San Diego, up the coast, to the Callaway vineyards in Temecula, for a fabulous weekend.
There is no way in God's green acre that your temp in SoCal matches up to our TX "London Broil" setting during summertime :shock: . But I've driven in blazing temperatures all over AZ, NV, NM, TX, and even overseas in Spain, Italy, and even Northern Africa in another life, and I've always bumped up my tire pressures. I'm not saying anyone else should do it, just sharing my life experiences for your (a) review, (b) kindest consideration, and (3) amusement.
Man, we looooove San Diego. The whole SoCal area is a national treasure. One of our most memorable drives through your part of the world took us from San Diego, up the coast, to the Callaway vineyards in Temecula, for a fabulous weekend.
There is no way in God's green acre that your temp in SoCal matches up to our TX "London Broil" setting during summertime :shock: . But I've driven in blazing temperatures all over AZ, NV, NM, TX, and even overseas in Spain, Italy, and even Northern Africa in another life, and I've always bumped up my tire pressures. I'm not saying anyone else should do it, just sharing my life experiences for your (a) review, (b) kindest consideration, and (3) amusement.
"My only concern with running really inflated is the hot-hot-hot roads here in San Diego in the summer (you can't stand barefoot in the street for more than 2 seconds!)"
Ran 45psi in mine all last summer in Phoenix with no problems, got a friend running his at 50. I would really recommend you bump em up because it lightens the load on the engine and ima which makes it better when you have your air conditioning going durring the summer. And don't skimp on the air either, if your hot so are the batteries which is not a good thing. (btw, on the highway ac on econ 80 degrees with the fan on full blast works pretty well and doesn't totally kill your mileage).
Ran 45psi in mine all last summer in Phoenix with no problems, got a friend running his at 50. I would really recommend you bump em up because it lightens the load on the engine and ima which makes it better when you have your air conditioning going durring the summer. And don't skimp on the air either, if your hot so are the batteries which is not a good thing. (btw, on the highway ac on econ 80 degrees with the fan on full blast works pretty well and doesn't totally kill your mileage).
but but.... what about my miles per gallon!Rick said:
the only time i turn on my A/C in the summer is on the freeway. when i slow down i roll down the windows because the outside temp isn't too hot. but the insight (even in grey!) becomes an oven with the windows up.
now the question is... do you get better mileage on the freeway with the windows rolled down? or the A/C on?
Well when it's 110 outside there really isn't much choice but to have the air on. I prsonally can't stand the noise of the windows rolled down on the freeway. Trust me on this, NiMH don't like heat. You can try just running with the windows down, but if you notice your only getting any less than full regen the car is limiting the input current because the batteries are overheating. Remember, the car can already be an oven after sitting and every time current moves through the batteries (which is constantly) some energy is lost to heat which makes it even worse. And I don't think you can justify saving a few ounces of gas here and there over the cost of a prematurely dying battery pack.
As far as mileage with ac on or windows down common knowledge says the aerodynamic gain with the windows up over the ac off wins and I would think this is especially true with the .25 cd Insight.
As far as mileage with ac on or windows down common knowledge says the aerodynamic gain with the windows up over the ac off wins and I would think this is especially true with the .25 cd Insight.
Silly question, is there an AC vent which goes back into the battery compartment? I loved pulling up the carpet cover in the back and reading " HIGH VOLTAGE! - YOU WILL BE KILLED IF YOU OPEN THIS COMPARTMENT!"
I noticed two vents, one on each side, which Im thinking might be for venting for the battery compartment, can someone confirm?
Michael
I noticed two vents, one on each side, which Im thinking might be for venting for the battery compartment, can someone confirm?
Michael
battery vents
NJinsight,
the vents in the rear on the sides are just for cabin ventilation and go to the outside. There is a vent for cooling/heating the battery pack and this is located behind the passenger seat.
There is no direct duct from the AC to the battery.
NJinsight,
the vents in the rear on the sides are just for cabin ventilation and go to the outside. There is a vent for cooling/heating the battery pack and this is located behind the passenger seat.
There is no direct duct from the AC to the battery.
i just inflated my tires back to 45-50psi (i can't get an accurate reading, but it's somewhere around there)
:shock: WOW what a difference it makes! i can now go up steady inclines at the same MPG i was getting when cruising on flat roads!
i think my pressure must have been pretty low before. maybe around 30. but all the gauges i use give different readings. does anyone know of an ACCURATE one?!!?
:shock: WOW what a difference it makes! i can now go up steady inclines at the same MPG i was getting when cruising on flat roads!
i think my pressure must have been pretty low before. maybe around 30. but all the gauges i use give different readings. does anyone know of an ACCURATE one?!!?
Ok, I was having a discussion with someone the other day about the Insight tires and how they wear at the edges first. Ok so here's the theory. Most of us run the tires at higher pressures. The rest run them at the recommended pressures, which 38 is still high compred to a lot of other car tires. Now, for the tire to be low rolling resistence the idea is it holds it's round shape better than a normal tire so the belt has to be a lot more solid. Now, common tire knowledge says that when you overinflate tires the centers buldge out and they wear in the center more. This has not proven true with our Potenza's. Could the fact be that the center of these tires is so strong that it holds tighter than the outer treads and allows the outer sides right by the sidewall to expand out more than the center?
If this didn't prove true then theoretically there would be some unsafe pressure we could inflate to (60psi?) which would push the centers out enough so that the entire tread would wear evenly. I'm starting to wounder because in a lot of cases these cars seem to be eating the outer treads of the tires in not only our Insight's but the Prius's also. My car with just under 13,000 miles is already starting to show signs of the outer treads wearing already. Even if this proved true, and underinflating would have a more even wear I'd just eat the cost of new tires and stay at my pressure. I'm curious if anyone could beat this theory down, or if it makes sense to anyone else.
If this didn't prove true then theoretically there would be some unsafe pressure we could inflate to (60psi?) which would push the centers out enough so that the entire tread would wear evenly. I'm starting to wounder because in a lot of cases these cars seem to be eating the outer treads of the tires in not only our Insight's but the Prius's also. My car with just under 13,000 miles is already starting to show signs of the outer treads wearing already. Even if this proved true, and underinflating would have a more even wear I'd just eat the cost of new tires and stay at my pressure. I'm curious if anyone could beat this theory down, or if it makes sense to anyone else.
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