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I know my Gen2 tire placard shows 36 psi as the correct tire pressure, but I wonder if any of you here have adjusted your TP to achieve certain goals. For most owners here, you probably think of MPG or eMPG. Other goals might be even tread wear or smooth ride.

If you were only concerned about MPG then you could jack up the pressure to the max on the sidewall (44) and be sure you're getting the lowest rolling resistance. But the ride would be rougher and the tires would wear in the center of the tread.

My "other" car is a 1999 Monte Carlo. It's placard shows 30 psi on all 4. That never made sense to me because it is very heavy in the front and the front tires at 30 look half flat. I've owned the car 18 years and I've been running 36 in the front and 31 in the back. I get even tread wear and I believe I've figured out what that car is happy at.

I am too lazy to look up the weight distro on my Volt but I'll bet it's a lot closer to 50/50 front/rear than my Monte is.

You guys have any ideas about this?
 

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Having owned THREE Volt's since March 2012 it's been my experoience that for a daily driver ride/comfort and most efficient driving I have found setting the tire PSI's to TWO PSI over the recommended setting. For my 2017 mine are set to 38 PSI on all four tires.

Remember that you need to set the PSI when the tires are COLD. Some will recommend HIGHER settings but that could compromise ride, noise and harshness.

So I recommend starting there and see how that works for you.
 

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I believe Chevy recommends 38 psi front and rear for the gen1. In my gen1 I ran 40 psi front and rear and I think I got an extra mile or two on EV. I too noticed the gen2 lower recommended pressure of 36 psi front and rear. I'm running 38 psi in them right now, but I haven't noticed a difference yet. It seems like 40 psi is the sweet spot, so I think i'm going to bump my gen2 up to 40 and see if there is any improvement in range.

You're right about the ride being a little more harsh, the higher you go in PSI, but honestly I swerve potholes when it is safe to do so to keep my alignment in check as long as possible so as long as you're not hitting every single pothole in the road, you may not notice the difference in ride comfort.
 

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I won't swear

I know my Gen2 tire placard shows 36 psi as the correct tire pressure, but I wonder if any of you here have adjusted your TP to achieve certain goals. For most owners here, you probably think of MPG or eMPG. Other goals might be even tread wear or smooth ride.

If you were only concerned about MPG then you could jack up the pressure to the max on the sidewall (44) and be sure you're getting the lowest rolling resistance. But the ride would be rougher and the tires would wear in the center of the tread.

My "other" car is a 1999 Monte Carlo. It's placard shows 30 psi on all 4. That never made sense to me because it is very heavy in the front and the front tires at 30 look half flat. I've owned the car 18 years and I've been running 36 in the front and 31 in the back. I get even tread wear and I believe I've figured out what that car is happy at.

I am too lazy to look up the weight distro on my Volt but I'll bet it's a lot closer to 50/50 front/rear than my Monte is.

You guys have any ideas about this?
I won't swear to this but one of my techie friends insists that one no longer gets uneven tire wear from over inflating tires because the belts on radials assure a flat foot print. On my last car I had the tires inflated to 45 from a recommended 32 and I did not see that sort of wear.
 

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One thing that scares me is that I think the tire pressure display is a couple of pounds low. I'd say this applies to most Volts. So if you jack the pressure to 44, they're actually at 46. Eventually one's going to pop. Has anybody else noticed the display is a couple of pounds low?
 

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No way should you use the car's display for setting tires. Buy yourself a digital gauge.

Then pump those tires up to the cold MAX Press as seen on the side of the tires. 44psi, 51 psi, etc.
Then watch your range and mpg numbers go way up !
The handling will be 'crisper' but the traction, especially wet, may go down a little because of the smaller tire 'footprint' on the road.
But man does the car roll easier!!

YMMV
 

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The Volt is a heavy car on a skinny tire. I keep them at 40. My handheld tire gage agrees perfectly with The TPMS reading. After running my first set of tires at the recommended 36 and finding accelerated edge wear, it seems 40 is the sweet spot.
 

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Don't forget that the ratings are based on the OEM tire. So if it says 30 PSI on the Monte Carlo, I'd guess the OEM tire was a sidewall rating of 38 PSI. 30/38 = 79% of sidewall max for what the manufacturer says is a good pressure for comfort. We all know that MPG increases with a little bit more pressure, let's call that 10%. 33/38 = 87% of sidewall.


So if you've got modern tires with a 44, 48, or 51 PSI sidewall rating, see what it looks like if you use the percentage of sidewall ratio. 79% of 44 is 35 PSI, for a 51 PSI tire it'd be 40 PSI.
 

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One thing that scares me is that I think the tire pressure display is a couple of pounds low. I'd say this applies to most Volts. So if you jack the pressure to 44, they're actually at 46. Eventually one's going to pop. Has anybody else noticed the display is a couple of pounds low?
IIRC, TPMS units are calibrated at atmospheric pressure @ sea level
Utah is significantly higher up, and that may be affecting your readings.

So while mine is perfectly accurate (I'm more or less at sea level, within 100m) and can be used to give me a real number, yours is probably only good for the safety factor (significant pressure change warning) and for noting the differences between tires.
But the actual number will not be meaningful to you.
 

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The first of the first generation Volts had a recommended pressure of 35 psi. Then that was upped to 36 psi (same tire). Like Bazinga I find inflating the tires to 2 psi above recommended works well. I know some use higher pressures in order to get better range but the ride can get a little harsh.
 

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Discussion Starter #11
Thanks for all of your comments! I think I'll bring mine up to 40 and see what the ride is like.
 

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Experiment, with factory tires they might be more prone to puncture at higher pressures, and I noticed you will see the low traction warning much more frequently if regen braking and hit a bump (means regen braking instantly stops) and you better be quick on the brake. This is really only noticeable in "L" since your foot might not be on the brake.

I set them to 38-40 in summer and maybe 32-34 in winter.
 

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If you were only concerned about MPG then you could jack up the pressure to the max on the sidewall (44) and be sure you're getting the lowest rolling resistance.
This is absolutely incorrect as a statement

It might be true for particular tyres in particular circumstances, but is NOT true for low rolling resistance tyres.

There is a very good chance you will increase the rolling resistance if you max the pressures on LRRs. This is because you will start getting 'damping' in the sidewalls rather than 'springy', which is one feature that makes LRR tyres LRR. Thin, bouncy sidewalls that spring back, rather than resist the deformation.

Think Willow tree versus Oak in a wind and all that.
 

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I run 45-50 psi. The OEM Goodyears have a sidewall rating of 51 psi. It seems to help me get more miles per charge, and the tires wear evenly.

GSP
 

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OEM Goodyears get terrible wear at tread shoulder run at anything approaching "recommended" pressure. And some places in the documentation 38 PSI is described as "recommended minimum pressure".
 

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OEM Goodyears get terrible wear at tread shoulder run at anything approaching "recommended" pressure. And some places in the documentation 38 PSI is described as "recommended minimum pressure".
I think the Gen 2 has Michelin's. However I agree about the Gen1 OEM Assurance tires. I ran them over 40 PSI the entire time and the shoulders still wore quicker than the tread. Bad design? Anyway I just replaced them on my 2nd Volt at 41k miles with Michelin Defenders. Much quieter better ride. I have them on both my Volts and very happy with them.
 

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This is absolutely incorrect as a statement

It might be true for particular tyres in particular circumstances, but is NOT true for low rolling resistance tyres.

There is a very good chance you will increase the rolling resistance if you max the pressures on LRRs. ...
Never heard this before. Where is your data?
This can easily be tested over 2 days of driving.

I have a bank courier friend that is all about efficiency. He sometimes runs his tires at 60 psi and has the data to back up his fuel mileage claims.
( The 'Max psi' on the tire is for 'Max load', also on the tire, in the worst conditions.)
 

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Here's how I set the tire pressure on my (Gen 1) Volt - First a couple of observations.
1) I have noticed with the use of several different pressure gauges that the TPMS readout on my display is very accurate.
2) If I set all 4 wheels to the same PSI when cold, they are all different when warm and cruising steady at highway speed. I assume due to weight distribution in the car or something.

So, I adjusted my tire pressures so that they are all slightly different when cold but all the same when warm. OE setpoint is 38, I have mine set differently all around but so that all 4 are 42 PSI at cruise. How's that for fine tuning? ;)
 

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I've been running 42PSI Cold for years, in both the OEM Goodyears and my current Bridgestone EP422+ tires. I've tried everything between 38 and 46 PSI. There is a definite range increase from 38 to 42. I don't notice as much between 42 and 46, but ride and handling start to suffer, which is why I stick with 42.


As a side note for anyone who still has the early OEM Goodyears from 2011, 2012 and maybe 2013 installed, there were a lot of sidewall blowout issues with those tires. Increasing pressure seems to help the issue.
 
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