Tire PSI and Back-up lights?

[scotty0607]

Hi, I have an aspire and was reading on the higher the tire pressure the better MPG. My recommended tire pressure is 35psi, so how much further can I take it up without it putting major wear on my tire?

Also I had to take the engine to replace the input shaft bearing on my tranny and since I'hv put everything back in my Back-up (reverse) lights stay on when the car is on?

[1988redfordfestiva]

i prefer 30 psi 35 makes a rougher ride your reverse switch might be bad or not hooked up mine did this before

[ghosthunter242]

higher mpg

i was part of the hypermiling website, green mpg for a while.
the goal was to beat the epa's estimate and the manufacture estimate of mpg.
i have a 2007 yaris and i think the psi was to be 32 or 35, it's been a while, but on the freeway, my average went from stock32/35psi at about 35-37mpg. i upped the psi to 45 and i got over 40mpg. i hesitantly bumped it up to 55psi and was averaging over 41mpg. the ride was a little stiffer, but not by much. no weird wear or problems at all. almost 30k miles on original tires and still fine.

but all that changed when the ethanol was mandated to be 10% in all gas. i went from an absolute average of 39.8mpg city/highway down to 31-33.
shell gasoline actually bumps my mpg's up by 2-3 mpg.(nitrogen, really?)

my last road trip(800 miles in 14 hours) in the car yielded an average of 43 mpg on ?psi and crap E10 gas. i am sure with 55psi and shell or non E10 gas would be closer to 50mpg. not festiva info per se, but hypermiling info none the less

[resuwrecked]

I found out that 45psi on s-rated tires going over 80mph will result in a blowout. I run either 32 or 35 in my cars. Remember that at higher psi you have less contact patch and will compromise wet traction.

Edit: when you start going over around 40psi your center tread will wear faster. I wouldn't go to 55 if driving over 65mph. I have seen cars come in the shop with over 100psi in the tires, like they go to the gas station, put a quarter in the air pump, clip on the line and wait for it to shut off lol.

[1988redfordfestiva]

http://www.alibaba.com/product-gs/200245343/back_up_lamp_switch_for_kia.html

i can get it if u need it

[Oren09]

but all that changed when the ethanol was mandated to be 10% in all gas. i went from an absolute average of 39.8mpg city/highway down to 31-33.
shell gasoline actually bumps my mpg's up by 2-3 mpg.(nitrogen, really?)

my last road trip(800 miles in 14 hours) in the car yielded an average of 43 mpg on ?psi and crap E10 gas. i am sure with 55psi and shell or non E10 gas would be closer to 50mpg. not festiva info per se, but hypermiling info none the less

The only gas choices here are Exxon and Cenex. The Exxon station says the premium contains no ethanol. Is it worth .20/gal more for ethanol free if it does affect mileage?
I'm not sure what pressure the Festy tires are at exactly, but they were in the 30s.
I keep my truck's 265/75 tires @ 70PSI. It rides really rough- you feel every tiny crack. But, I can get up to 17MPG highway, and 11-14 city.
My Festiva is averaging 38MPG, btw.

[ghosthunter242]

if one's idea is to achieve higher mpg than you will not have to worry about 80 mph.
the goal would be to keep kinetic energy and brake the least amount possible. accelerate slowly and smoothly and keep the mph between 55 and 65.
i would go to some hypermiling websites before you got too discouraged.
there is a lot of info out there. the best thing to improve is the driving style. then the simple things like tire pressure. oh yeah, the contact patch between the road and tire will be reduced in the wet braking. but it is not that detrimental. i live in the great pacific northwest. we get more rain than you and i never had a problem. if you keep a safe distance as you should anyways between the car in front of you than it is not an issue.hope that helps. higher mpg is fun if you make it. coasting down hills. there is a 'pulse and glide' method that really involves the driver. coast down any grade you can and get about 5mph over the speed limit and coast it down 5mph under. this will up the mpg 1 or 2mpg.
ethanol gave me a huge mpg drop. almost 30% and is still costs more..i would pay the 20 cents more if i could but not possible. the stations that refused to comply here all got bulldozed and became car washes.

[scotty0607]

Thanks for all your replys! I'm going to boost my pressure from 35 to 45 and see what happens. Also about the backup lights when I took the engine and tranny out I did remove the backup light sensor and ever since I put it back in it does work right, could I have put it in to tight possibly or? Thanks again guys!