bobloblawGTI
Autocross Champion
- Location
- DC
- Car(s)
- 19 GTI SE 6MT
Door jam says 39psi, consensus is run 37 for comfort?
7
Anyone trade their mk7 for something more comfortable?
- Thread starter sjnbgti
- Start date
victorofhavoc
Autocross Champion
- Location
- Kansas City
I think people are over simplifying things here.
For oe tire size, the oe tire pressure is based on the load rating, weight of the vehicle, alignment, and tire class. If you change any of these things, then the pressure spec should change as well. If you don't, stick to oe.
For example, more camber means you can run lower pressure and avoid the tire rolling over still. If you go with a wider tire or a different sidewall size that changes your load rating, pressure should go up or down accordingly. If you lighten your vehicle or you routinely carry hundreds of pounds of stuff/people, you should decrease or increase your pressure accordingly.
General rule of thumb is to start at the door spec on oe sizing and then change psi by 3 or so up and down to get the handling you want while keeping tire wear flat and consistent. If you go too low, you'll wear the inner and/or outer edge too much and lose gas mileage. It may feel more comfy, but a sharp pothole could also bend your rim sooner if it's too low.
Keep in mind oe safeguards take into account where the low pressure warning kicks on. If you set it low, then it will alert when it's even lower. Whether that's in a bad spot for you and your setup is totally up to you (and your setup).
frankysharpp
New member
- Location
- Qc, Canada
- Car(s)
- GTI Mk7.5 2021
I ride on a Mk7.5 DCC stock suspension and I love the good balance of it. Summer and winter tires are set on oe 18” wheels, pressure to 38-39psi. I would say the road condition could be the biggest factor of discomfort but most of the time I ride the suspension in “normal” mode. “Comfort” mode definitely help on harsh road/winter. Compared to the regular mk7 trendline on 17” wheels of my wife, I would say the biggest comfort difference that I feel between her Golf and my GTI in “comfort”mode is the wheel size.
We are far from being anywhere near the load index rating limits... the 19in sizing (235/35) have a load rating of 91, at 36psi they are rated for 1,356lb per corner (over 5,400lb.... the GTIs are ~3.1k lbs, the Rs ~3.4k)
I would not go below 37 psi because of uneven wear however, I ran my old tires too low it seems, usually 34-36 and by the end, I had ~2-2.5mm in the shoulders but the central grooves where ~3.5-4mm...
Like I mentioned above, turns out they where super harsh riding... my new tires are way way softer riding, I can fill them up to 39psi no problem.
(Note the R's OE alignment has a bit more camber up front, but I doubt it makes much difference.... also 95% of the time its just me in the car, never take a lot of weight.)
victorofhavoc
Autocross Champion
- Location
- Kansas City
You're totally correct. Also important to keep in mind the gti and r are like 61% weight up front...
3166 is what my gti weighs fueled with nothing in the hatch, not even a spare or tools, no floor mats, nothing in the doors, nothing in the glovebox.
That's 1931lbs up front. About 966lbs per tire.
92xl on the factory 225/40/18 is 1389lbs @42psi and crosses 966lbs @ roughly 27psi.
Tpms sensor goes off when 25% low by typical standards. This means if you set it to 36psi and don't pay attention, when your light comes on, you're probably already in flat tire territory.
Add people, stuff, and other things and that could be way too low. Not a problem if you're checking your tire pressures weekly and before every longer drive. Could be a big problem if you're someone that doesn't pay attention much.
MADPWR
Passed Driver's Ed
- Location
- Chicago burbs, IL
- Car(s)
- 2018 Golf R
hans611 referenced this post on another post that me and him are talking about tires. In case this info is helpful, here is what I wrote in my other post:
I am surprised how extreme of a comfort difference the various tires I have had on this car have been. The only other time I saw this much of a comfort difference was when I replaced grand touring V-Rated tires for cheap S-Rated tires on a car when I listed it for sale, but that S-Rated tire also had an extremely squishy sidewall and a huge drop in performance.
I really disliked how my car rode on Continental ExtremeContact DWS 06 performance all-season tires. Ever bump felt like I was riding on the metal wheel without a tire. They also greatly hindered the car's driving performance, but they were uncomfortable tires. I was so happy when I put on the Michelin Pilot Sport 4S tires. It made a word of difference in making the car comfortable to drive and obviously far more sporty. If I were to go on a test drive with those Continental ExtremeContact DWS 06 tires and then test drive it with these Continental ExtremeContact Sport 02 tires, I would have sworn the cars had different suspensions. The comfort difference between those super harsh all seasons and these super soft summers is just way too much to think it was just tire alone making all of that difference.
Also, in regard to PSI, I have been running 39 to 39.2 PSI on all four tires since I got the car. All my sets of wheels are Golf R OEM running 235/35/19 tires. My driving style is what you would call very spirited (which would be an understatement), and I have had quite even wear across the various sets of tires I have run. I know the front alignment factory setting has a slight negative camber. Also, my front wheels keep shifting to toe out between alignments, but toe out doesn't bother me since I do a lot of quick lane changes. It does however wear out the inner shoulder of my front tires quicker though. I have an air compressor in my garage, and I use the most accurate digital tire inflator I have been able to find (Astro Pneumatic 3018). I adjust the pressure every 1-2 weeks. Since I always loose a tiny amount of PSI in that time frame, I usually go to 39.2 PSI. Just as a reminder for anyone who is not aware, the car's door tag PSI rating is a cold rating. So, the tires/wheels need to be fully cooled before adjusting the pressure. I have a heated garage, so in winter time I have to compensate for the indoor vs outdoor temp by adding 1 PSI for every 10 F degrees that my garage is warmer than outside.
I am surprised how extreme of a comfort difference the various tires I have had on this car have been. The only other time I saw this much of a comfort difference was when I replaced grand touring V-Rated tires for cheap S-Rated tires on a car when I listed it for sale, but that S-Rated tire also had an extremely squishy sidewall and a huge drop in performance.
I really disliked how my car rode on Continental ExtremeContact DWS 06 performance all-season tires. Ever bump felt like I was riding on the metal wheel without a tire. They also greatly hindered the car's driving performance, but they were uncomfortable tires. I was so happy when I put on the Michelin Pilot Sport 4S tires. It made a word of difference in making the car comfortable to drive and obviously far more sporty. If I were to go on a test drive with those Continental ExtremeContact DWS 06 tires and then test drive it with these Continental ExtremeContact Sport 02 tires, I would have sworn the cars had different suspensions. The comfort difference between those super harsh all seasons and these super soft summers is just way too much to think it was just tire alone making all of that difference.
Also, in regard to PSI, I have been running 39 to 39.2 PSI on all four tires since I got the car. All my sets of wheels are Golf R OEM running 235/35/19 tires. My driving style is what you would call very spirited (which would be an understatement), and I have had quite even wear across the various sets of tires I have run. I know the front alignment factory setting has a slight negative camber. Also, my front wheels keep shifting to toe out between alignments, but toe out doesn't bother me since I do a lot of quick lane changes. It does however wear out the inner shoulder of my front tires quicker though. I have an air compressor in my garage, and I use the most accurate digital tire inflator I have been able to find (Astro Pneumatic 3018). I adjust the pressure every 1-2 weeks. Since I always loose a tiny amount of PSI in that time frame, I usually go to 39.2 PSI. Just as a reminder for anyone who is not aware, the car's door tag PSI rating is a cold rating. So, the tires/wheels need to be fully cooled before adjusting the pressure. I have a heated garage, so in winter time I have to compensate for the indoor vs outdoor temp by adding 1 PSI for every 10 F degrees that my garage is warmer than outside.