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No other changes psi is the same (50hot)

I just replaced the worn out, few mm left on the tread, probably old re92 tires with fresh new ones.

It made such a huge impact, I cant even coast down hill and regen. I have to give it some gas downhill!?

On level ground it takes significantly more throttle, im in the 40%range now, to slowly accelerate.

Going uphill, even mild grades, i need to command batt assist JUST to keep speed, and i really have to give it gas with the assist (60+ %) to have it accelerate slowly. (Im talking about slow for an insight)

Ive read the mpg goes down a bit with new tires, but I cant believe the difference. Im guessing that at my altitude (6000+) the small amount of power/torque headroom I had with the old tires to accelerate with is completely eliminated with the softer taller tires.

This is all with the a/c completely off, city driving up to 40mph.

With a/c on?! OH MY GOD i have to literally floor it to even accelerate at all. 100% throttle, and its accelerating 1mph per second when the compressor is on.

This is brutal.

Im going to try MUCH higher tire pressures (going to try 80f/75r), this is rediculous, i need to travel cross country soon, with about 500 pounds of extra weight, i wont even be able to drive. And Im almost out of money, i cant afford to put the old tires back on.


Will update as soon as I find a shop that will double the posted sidewall pressures.
 

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*driving


It made such a huge impact, I cant even coast down hill and regen. I have to give it some gas downhill!?

On level ground it takes significantly more throttle, im in the 40%range now, to slowly accelerate.
Agree, the tires are terrible when you first put them on, but they will improve considerably over just the first 500 miles or so. By the time you get 1000 miles, the "new" impact will be barely perceptible in my experience.

Your elevation is definitely a negative since you are operating at a very thin margin for best efficiency.

Don't get too upset. Just be a little patient with them. By the time you get to Kanab you will be back in pretty good shape - and they will still improve.
 

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Discussion Starter #3
So tire pressures are now 80 front 75 rear. Or 75 70, the gauge was hard to read...

Im still using 10% more throttle than before, and around 10mph slower than before on top of that.
 

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150psi is as high as I have gone.in ten days down to 130 .no change in mileage..For me no need to go over 120 psi.RE92's of coarse.my tires 3pluse years old.good luck on 75 psi!
 

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New tires weigh more than old an worn.Rotational mass look it up give answer.and the rubber must get conditioned.
 

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Discussion Starter #7
150psi is as high as I have gone.in ten days down to 130 .no change in mileage..For me no need to go over 120 psi.RE92's of coarse.my tires 3pluse years old.good luck on 75 psi!
How much data is there on the safety of running 120psi? Most of the threads ive found are filled with "50psi was too harsh (lol) i went back down to 30psi"

Huh, thats the first ive heard of tire conditioning. Is that like heat cycling a race tire properly? So with the re92 tires the friction must go down during the first few heat cycles?
 

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How much data is there on the safety of running 120psi?
"data"? Hah! Nothing more than the anecdotal evidence of Nathan not having died doing it, yet.

But if one of them ever does suddenly give out on him, "Thar she BLOWS!", it's going to be like that steam engine in Johnny Cash's, "John Henry song"; there's going to be parts of it spread all over the mountain.
 

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A while back, I was one of the first people to arrive at an accident where a tire blowout resulted in the car flipping over. <edit>graphic details removed</edit>

A blowout can involve multiple vehicles on a busy highway.
 

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If you drive the tires at sidewall recommendation. To me that's driving a flat tire. They get hot real fast and destroy the tires from the inside out. Just drive a 35 pound air pressure tire at 25 psi and you can roast marshmallows on it. Go the other way more air pressure The tire does not flex and get super hot. Your motor does not work hard either. And the mileage goes way up. Tire is less likely to blow out because no flex no heat no self destruct tire so tires companies can sell you more tires. There's airplane tires that have 300 psi. Anyway it makes sense for me I tested it for the last two years. I think 200 psi on a new tire for a little aluminum car you would have no problem. I've driven semi trucks for years 110 psi and then put 70,000 pounds of grain on them and drive down the highway. My little car only has 500 pounds per tire ifI'm in the car.and I have leg press 3000 pounds when I was young several times. Or lifted it 4 inches . .
 

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I want to be sure your new RE92s are 165/65X14. Any other size tire will cause the symptoms you describe.

Sam
 

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*driving

No other changes psi is the same (50hot)

I just replaced the worn out, few mm left on the tread, probably old re92 tires with fresh new ones.

It made such a huge impact, I cant even coast down hill and regen. I have to give it some gas downhill!?

Check for brake drag.

Im going to try MUCH higher tire pressures (going to try 80f/75r), this is rediculous, i need to travel cross country soon, with about 500 pounds of extra weight, i wont even be able to drive. And Im almost out of money, i cant afford to put the old tires back on.


Will update as soon as I find a shop that will double the posted sidewall pressures.
I doubt any reputable shop will over inflate your tires that much. To much could go wrong and they could be liable.

55-50 psi is more the "normal" over inflation pressure for RE-92s,
 

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Just looked at a video on YouTube . Said truck tires like on my Ford truck would explode at 600 psi. They blew up an old one that was damaged it blew at 300 psi.The video is called -------detonating a tire in the cabin.-------I don't notice any gains in overinflation past 130 psi.
 

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Discussion Starter #16
I've been having trouble finding a free pump that could inflate my tires more. Been running 80psi, want to bump it up a little more, like maybe 110 front 100 rear.

Just did a HOT compression test. cylinders from drivers side to passenger side... 165,150,160psi

Drove around with the top O2 sensor out, didnt feel a change, I'll try to pull the cat tomorrow and really take a good look.

Also, someone suggested my car isnt going into lean burn, but it IS doing the drop in mpg on the highway for a few seconds, then going back to the previous spot on the mpg gauge.

I have to look into the settings on my obd2 c&c, another person suggested I have the afr settings in the wrong spot? I don't recall changing something, but I have to look at the manual and see if I can adjust something.
 

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I've been having trouble finding a free pump that could inflate my tires more. Been running 80psi, want to bump it up a little more, like maybe 110 front 100 rear.
Watch your tire wear with the higher pressure. With 80 PSI in mine for about 10K miles on tires that had close to 10K when I bought the car (so 20k total), my fronts have half tread left and the rears have about 80%-90% tread left. Fronts are also wearing a little uneven. I also haven't checked tire pressure in a few months, so they may be down a few PSI now. I also tend to corner a little too hard (conservation of momentum lol) so that's probably a factor as well.

Also, someone suggested my car isnt going into lean burn, but it IS doing the drop in mpg on the highway for a few seconds, then going back to the previous spot on the mpg gauge.
If you're getting NOX purges then you're getting lean burn.
 

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Discussion Starter #18
I think the uneven tire wear should be due to cornering too fast, not really due to the psi. Just a guess though. I do turn as fast as possible without scrubbing the tires hard. Much faster than a sane person would turn, but listening and feeling the tires I'm not pushing them.

I just read through the full obd2 c&c manual, and didnt find anything illustrating an afr setting change, only that you must have the afr parameter selected to be shown for the green lean burn led to turn on. My afr doesnt go higher than 14.3, and only goes lower, to 13.5 or so when I go heavy on the TPS%
 

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Dear Sir -----i'm The fellow who has 130 PSI tires .I would advise not to go over 100. I have very fine roads to drive on. If you turn into a road and it has loose gravel on the asphalt you will not recover The upcoming tailspin. There is a drastic loss of traction that also gives you better mpg. I would just up your pressure 5 pounds a month and acquire knowledge of the new way your car will respond to road conditions. That's the way I did it. I wrote about it two years ago on "just got to know. "----------------------------------please take my recommendation seriously ease into it. Your car is at stake and maybe your life . Good luck to you on your endeavors! Regards "your friend "Nathan ---I love the smell of aluminum in the morning!
 
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