I just thought I'd post this for everyone's benefit as recently this applied to me.
So the other week I decided to get some new AT tyres installed on my Patriot. 235/55/r17 out. 225/65/r17 in.
Now as I understand, though I may be slightly inaccurate, the stock tyre size for 17 inch rims for the Patriot is 215/60/r17. It may also be 215/65/r17.
But many All-Terrain tyres are often produced in bigger sizes. More especially wider, but also taller too.
The tyre I decided to go for was not available in my old 235 spec. So it was either 225/65/r17 or 235/65/r17. Browsing this forum, it appears that 235/65/r17 does not fit most stock Patriots with no lift nor spacers. Some members had success, others didn't. But considering I use full-lock to park every day at the tiny private car park I use at home, I did not wanna risk any tyre rubbing, so going for the 225/65/r17 just seemed like the sensible option.
Problem is - going wider and shorter to this new taller and narrower size, threw my speedo off.
Using online converters, my speedo was predicted to be showing 60mph, when actually travelling at 64mph. That's not great. Furthermore, going faster than your speedometer is showing, means your odometer will slightly undercount your mileage, by the smallest of margins, but enough to make it inaccurate. It had definitely thrown my speedo off anyway, as it was definitely saying I was going a few mph less here and there, then what my GPS was recordimg.
Solution:
There is a way round this, to get your speedometer and consequently your odometer, working accurately again.
TOOLS NEEDED:
OBDII scanner
Android/Iphone with downloaded app "JScan"
Tape measure
1. OBDII scanner: There are a number available on amazon, which I personally dislike using but seems to be one of the easiest places to find them. Here is the one I bought:
Also recommended on another jeep forum/YouTube video I watched. Slightly cheaper:
2. When you have your OBDII scanner - you need to download the app "JScan" on your Android/Iphone.
At some point upon opening the app and selecting the relevant options in setup, you should be prompted about a licence. I believe you do need to buy a licence. Which costs about $20 I recall. Once you've done that you can presumably change any settings you want, (which are applicable in Jeep Patriots) incl tyre size.
3. When you have the OBDII scanner connected in the OBDII port (which for me in the UK is between my knee and my foot above the accelerator pedal), and you're connected via bluetooth on the Jscan app on your phone to your OBDII scanner, you then need to measure your tyre.
There are websites such as: Tire Size Converter - which will convert your new diameter tyre size to inches (which should be around 28inch mark probably.) But I was reading - apparently you need to actually measure the tyre as it will often be different. So, do correct me if I'm wrong anyone, but the way to do this is take your tape measure and measure from the top of the tyre to the bottom of the tyre apparently.
JScan had my stock tyre size diameter as 26.5 inches. According to tyresize.com - the 225/65/r17 should be about 28.5 inches. Yet I measured top to bottom and get just over 27 inches. So I adjusted my tyre size accordingly and now the speedo is pretty much dead-on. Confirmed via GPS on google maps and "Car Scanner ELM OBD2" app for iOS, an app which the Veepeak instructions also tell you to download. You can view a whole heap of sensors in that.
Final step - Using JScan to Change Tyre Size
Here is an easy-to-understand walkthrough:
PLEASE NOTE:
1. I had connection issues with my Veepeak OBDII scanner and had to retry connecting multiple times, for some unknown reason. I played around with closing the app and disconnecting and reconnecting the OBDII scanner, and also using it with the engine actually switched on, which you can do of course. In the end, I forgot what got it working, but mine was a bit troublesome, but once connected, worked fine.
2. When you submit your tyre size changes, wait for the change to process. It took about 1-2 minutes for me, so just be patient and don't go off the app.
3. I did have a brief moment last night after changing my tyre size and going for a practice drive for about 20 miles, that when I got back to my place and parked up and was looking at various things on JScan, my ABS light suddenly came on and started flashing orange with the engine running. I wonder whether I did something wrong on the app, but I didn't change any other settings so this was a bit of shock. I went out today though, OBDII scanner disconnected, and the light never came back on, so perhaps a glitch.
So a word of caution: DO NOT CHANGE ANY SETTINGS YOU'RE UNSURE OF.
I hope this helps everyone. Because I had to do a bit of investigate work to realise this is actually possible doing yourself, without going to a jeep dealer/mechanic that may charge you a whole lot more, and it is just so easy. Anyway, enjoy.
So the other week I decided to get some new AT tyres installed on my Patriot. 235/55/r17 out. 225/65/r17 in.
Now as I understand, though I may be slightly inaccurate, the stock tyre size for 17 inch rims for the Patriot is 215/60/r17. It may also be 215/65/r17.
But many All-Terrain tyres are often produced in bigger sizes. More especially wider, but also taller too.
The tyre I decided to go for was not available in my old 235 spec. So it was either 225/65/r17 or 235/65/r17. Browsing this forum, it appears that 235/65/r17 does not fit most stock Patriots with no lift nor spacers. Some members had success, others didn't. But considering I use full-lock to park every day at the tiny private car park I use at home, I did not wanna risk any tyre rubbing, so going for the 225/65/r17 just seemed like the sensible option.
Problem is - going wider and shorter to this new taller and narrower size, threw my speedo off.
Using online converters, my speedo was predicted to be showing 60mph, when actually travelling at 64mph. That's not great. Furthermore, going faster than your speedometer is showing, means your odometer will slightly undercount your mileage, by the smallest of margins, but enough to make it inaccurate. It had definitely thrown my speedo off anyway, as it was definitely saying I was going a few mph less here and there, then what my GPS was recordimg.
Solution:
There is a way round this, to get your speedometer and consequently your odometer, working accurately again.
TOOLS NEEDED:
OBDII scanner
Android/Iphone with downloaded app "JScan"
Tape measure
1. OBDII scanner: There are a number available on amazon, which I personally dislike using but seems to be one of the easiest places to find them. Here is the one I bought:
Also recommended on another jeep forum/YouTube video I watched. Slightly cheaper:
2. When you have your OBDII scanner - you need to download the app "JScan" on your Android/Iphone.
At some point upon opening the app and selecting the relevant options in setup, you should be prompted about a licence. I believe you do need to buy a licence. Which costs about $20 I recall. Once you've done that you can presumably change any settings you want, (which are applicable in Jeep Patriots) incl tyre size.
3. When you have the OBDII scanner connected in the OBDII port (which for me in the UK is between my knee and my foot above the accelerator pedal), and you're connected via bluetooth on the Jscan app on your phone to your OBDII scanner, you then need to measure your tyre.
There are websites such as: Tire Size Converter - which will convert your new diameter tyre size to inches (which should be around 28inch mark probably.) But I was reading - apparently you need to actually measure the tyre as it will often be different. So, do correct me if I'm wrong anyone, but the way to do this is take your tape measure and measure from the top of the tyre to the bottom of the tyre apparently.
JScan had my stock tyre size diameter as 26.5 inches. According to tyresize.com - the 225/65/r17 should be about 28.5 inches. Yet I measured top to bottom and get just over 27 inches. So I adjusted my tyre size accordingly and now the speedo is pretty much dead-on. Confirmed via GPS on google maps and "Car Scanner ELM OBD2" app for iOS, an app which the Veepeak instructions also tell you to download. You can view a whole heap of sensors in that.
Final step - Using JScan to Change Tyre Size
Here is an easy-to-understand walkthrough:
PLEASE NOTE:
1. I had connection issues with my Veepeak OBDII scanner and had to retry connecting multiple times, for some unknown reason. I played around with closing the app and disconnecting and reconnecting the OBDII scanner, and also using it with the engine actually switched on, which you can do of course. In the end, I forgot what got it working, but mine was a bit troublesome, but once connected, worked fine.
2. When you submit your tyre size changes, wait for the change to process. It took about 1-2 minutes for me, so just be patient and don't go off the app.
3. I did have a brief moment last night after changing my tyre size and going for a practice drive for about 20 miles, that when I got back to my place and parked up and was looking at various things on JScan, my ABS light suddenly came on and started flashing orange with the engine running. I wonder whether I did something wrong on the app, but I didn't change any other settings so this was a bit of shock. I went out today though, OBDII scanner disconnected, and the light never came back on, so perhaps a glitch.
So a word of caution: DO NOT CHANGE ANY SETTINGS YOU'RE UNSURE OF.
I hope this helps everyone. Because I had to do a bit of investigate work to realise this is actually possible doing yourself, without going to a jeep dealer/mechanic that may charge you a whole lot more, and it is just so easy. Anyway, enjoy.
