55+ psi tire pressure... any reason for that?

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menkster

Member
Joined
Jan 9, 2017
Messages
6
I recently purchased a used 2013 Leaf (about 3 weeks ago). Previous owner had tires changed within the last few months, not sure where they got them changed.

I purchased an OBD unit (Konnwei KW902) and ran LeafSpy while on the road. LeafSpy displayed the pressure as 58 psi. I read in the manual and on these forums that tire pressure should generally be around 35-40 psi, so I thought wth... that can't be right. I then used a cruddy digital gauge and measured each tire to be around 47 psi. Then I used another cruddy portable air compressor with built-in gauge to measure tire pressure and got around 55 psi.

Regardless, it appears my tire pressure is well above 40 psi. My question is... is there any reason this might be? Maybe there's something I don't understand about tire pressure. The tires themselves say max pressure 35 psi, so I thought that was concerning. Can they even be inflated to 55 psi if it says max pressure is 35 psi??? Also, the car seems to drive fine, which is mainly why I didn't think there was any reason for concern. Then again, it's the only Leaf I've ever driven so I have no comparison point.

Should I deflate until the TPMS readings on LeafSpy read 40ish? Or should I just leave them be if they've operated this long without seeming to be troublesome?

Thanks!
 
I doubt the tires themselves say 35psi max. Most modern tires (in the size range we're talking about here) are either 44psi or 51psi max.

44psi is recommended by a lot of Leaf owners as it seems to be a good balance of handling and increased mileage (maybe 10%). I'm currently running about 42psi up from 35psi. My miles per kWH went from 3.7 to 3.9, about 5.5% better.

Where are you getting the idea the tires are 35psi max? The card on the door doesn't list the max pressure of the tire, just what Nissan recommends. (They likely bias it softer for better ride.)
 
The 36psi on the door label is too low, and the tires are too high. 38-44, depending on softness of ride desired, is the correct range for a Leaf. I do 40-42.
 
Note that tires heat up a lot while driving, which increases the pressure. So don't worry about the tire pressure being way high while on the road.

When you're filling them up & setting the pressure, the tires should be cold.
 
menkster said:
I recently purchased a used 2013 Leaf (about 3 weeks ago). Previous owner had tires changed within the last few months, not sure where they got them changed.
...The tires themselves say max pressure 35 psi, so I thought that was concerning. Can they even be inflated to 55 psi if it says max pressure is 35 psi???
I haven't seen 35 max PSI tires since the 80s.....everything new seems to max out at 44 psi or higher. If those replacement tires are indeed 35 max psi(your reading this off the tires and not door jam of car??) then personally I would NOT go above 35 psi, max is max. Sure it can be pushed and they probably wouldn't blow, but why take a chance. Again personally I like to run with the MAX tire pressure on cars or a tad less, but not really more, well unless very cold weather is very close and then I may go up to 10% more, but never almost double :shock: which it sounds like your tires may be inflated to.
 
skhmc said:
Where are you getting the idea the tires are 35psi max? The card on the door doesn't list the max pressure of the tire, just what Nissan recommends. (They likely bias it softer for better ride.)

nope. they do it to get better prices for the tires they need. Care to figure out how much a 15% reduction in tire life is worth?
 
skhmc said:
I doubt the tires themselves say 35psi max. Most modern tires (in the size range we're talking about here) are either 44psi or 51psi max.

44psi is recommended by a lot of Leaf owners as it seems to be a good balance of handling and increased mileage (maybe 10%). I'm currently running about 42psi up from 35psi. My miles per kWH went from 3.7 to 3.9, about 5.5% better.

Where are you getting the idea the tires are 35psi max? The card on the door doesn't list the max pressure of the tire, just what Nissan recommends. (They likely bias it softer for better ride.)

Hmmm... okay, well it helps me to know this is unusual enough that you doubt it.

This is why I think the tires are 35psi max... am I interpreting it incorrectly?

HfDlWMuDrg_x2WSqqMrmJVzBkhPqrMF2hGGbeK_c2LP3LZzSQtK7gc1s92n-BiTZZmEP-v0JnBiW4wc=w1366-h638-rw

romFbnaUUYcqyqNN9UEzuxF_24BpFFd2ESdbqcFAyWTcl_eOW7S6X8sGI3dXs3zXZRprgbqUl8eu-VE=w1366-h638-rw
 
jjeff said:
I haven't seen 35 max PSI tires since the 80s.....everything new seems to max out at 44 psi or higher. If those replacement tires are indeed 35 max psi(your reading this off the tires and not door jam of car??) then personally I would NOT go above 35 psi, max is max. Sure it can be pushed and they probably wouldn't blow, but why take a chance. Again personally I like to run with the MAX tire pressure on cars or a tad less, but not really more, well unless very cold weather is very close and then I may go up to 10% more, but never almost double :shock: which it sounds like your tires may be inflated to.

Okay... I thought maybe there's something I didn't know about tires but I guess it's as straightforward as it seems. I don't know what crazy-ass tire shop the previous owners took the car to, but I'll let the air out to 35 psi cold and maybe chance some over-pressure when they're warm, since... I mean... they're currently at like 57 psi.........
 
So, Menkster, can you verify that 35psi maximum is actually stamped on the tires? Maybe they are Chinese bargain basement units, in which case I'd replace them.
 
LeftieBiker said:
So, Menkster, can you verify that 35psi maximum is actually stamped on the tires? Maybe they are Chinese bargain basement units, in which case I'd replace them.

Did this photo count as verification?
HfDlWMuDrg_x2WSqqMrmJVzBkhPqrMF2hGGbeK_c2LP3LZzSQtK7gc1s92n-BiTZZmEP-v0JnBiW4wc=w1366-h638-rw


I'm conflicted whether to call them low quality or high quality because on one hand, they claim to be max 35 psi... on the other hand, they seem to be running fine on 55 psi as opposed to exploding...
 
menkster said:
LeftieBiker said:
So, Menkster, can you verify that 35psi maximum is actually stamped on the tires? Maybe they are Chinese bargain basement units, in which case I'd replace them.

Did this photo count as verification?
HfDlWMuDrg_x2WSqqMrmJVzBkhPqrMF2hGGbeK_c2LP3LZzSQtK7gc1s92n-BiTZZmEP-v0JnBiW4wc=w1366-h638-rw

Image isn't coming through. Google+ isn't very friendly about linking. Use something else like imgur.

I'm conflicted whether to call them low quality or high quality because on one hand, they claim to be max 35 psi... on the other hand, they seem to be running fine on 55 psi as opposed to exploding...

That's a lot like saying that it must be safe to drive at 80 in a 50 zone in the rain, I do it all the time with no problems...

If the sidewalls really do say 35 psi max, as Leftie said those are probably crap tires. Your car was probably a lease return and since the OEM Bridgestone Ecopias are well known for not making it to the 3 year mark of most leases, the last person to have it likely put the cheapest crap he/she could find that met NMAC's inspection standards since the car wasn't going to be a keeper. Or the dealer who ultimately sold the car did that to boost his profits but still be able to boast "new tires" in the ad.

Either way, you'll want to replace them sooner than later, and lower the tire pressure NOW. You don't want to find out just what the tire's limits are when you hit a minor bump or obstacle on the road that wouldn't flatten it at the proper tire pressure, and now you're hurtling out of control towards that bus thanks to a blowout.
 
Yeah, I wouldn't run with an extra 20 psi in the tires. There's overinflating and then there's OVERINFLATING.

I'd drop them down to around 40 psi if I were you, or maybe 45 if you're daring.
 
LeftieBiker said:
So, Menkster, can you verify that 35psi maximum is actually stamped on the tires? Maybe they are Chinese bargain basement units, in which case I'd replace them.

Unless range is an issue, it'd probably be most economical to just run the tires until they wear out and then replace them. Even if you get a bit worse efficiency, the difference probably won't be enough to cover the cost of new tires. From an environmental standpoint, it's also probably worse throwing out a perfectly good tire with its sunk energy costs, only to get slightly higher mileage.
 
My concern was with the idea of cheap tires that had been severely overinflated for a significant length of time. I wouldn't trust them not to blow out even at the rated pressure.
 
I also can't see the photos but it's pretty straight forward, if the OP has read the tires and they do indeed say 35lbs max on the sidewall, I'll take their word for it, I mean tires of many years ago use to max out at 35lbs and possibly cheap Chinese tires still do(OP, what brand are they?) that said since they probably are "cheap" tires it would be one more reason to not over inflate them. Sure they haven't blown yet, but do you want it to happen when going 70mph down a busy freeway :shock: no I'd immediately lower the pressure to no more than max inflation pressure when cold. Don't worry about what they get to warm, max inflation pressure is always cold and they assume the tires will get to a higher pressure when warm, that part is built in the spec. What you don't want is to over inflate the tires when cold, then they'll get even more over inflated when hot.
I believe exactly what someone else said, the car was a lease return and either the previous owner got the cheapest POS they could to pass the inspection or possibly the seller did the same, to be able to advertise "new" or slightly new tires, but I'd more suspect my first scenario.
Leftie biker made a valid point too, it's just how safe you feel with possible sub standard tires, I mean a set of 4 new "good" tires is probably going to cost you close to $500 mounted and balanced, thats your call.....
 
I know I sound like a broken record, but...

Don't replace anything, and just leave things alone at 35psi and drive the car until you need new ones.. why spend $$$ that you don't need to spend????
 
powersurge said:
I know I sound like a broken record, but...

Don't replace anything, and just leave things alone at 35psi and drive the car until you need new ones.. why spend $$$ that you don't need to spend????

Because the OP's safety, and the safety of others, is important. Leftie rightfully mentioned concerns about using such a tire if it's been severely overinflated for so long. Another thing I'm concerned about is whether these tires have a sufficient load rating for a car as heavy as the Leaf. With such a low max pressure printed on the sidewalls, there's a good chance they're not.
 
Thanks everyone! I'll definitely at least lower the pressure as opposed to keeping the current inflation. I had also wondered about the effects of prolonged overinflation... of course better safe than sorry and just replace, but easier said than done (or spent). :| At the same time, the visual of having a tire blow out then careening into oncoming traffic is quite visceral...
 
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