: New ATS 2.0 Turbo Lux: Tire pressure and tire monitor questions?



flycaster
04-04-13, 01:40 PM
It is truly very interesting how far Cadillac has gone to imitate the present BMW 3 series. It appears that they have even gone down to the same tire pressure recommendations (32psi fronts, 35psi rears) as BMW; at least these were also the recommendations for my 2002 325i. Now, to be quite honest, the ATS doesn't drive nearly as tight as the 325, but then again, nor do the BMW3's since 2006 (that's when BMW went "soft" steering with a generally softer ride in order to attrach a larger segment of buyers). For my 325 I had the tires set at 35psi all around and would like to do the same with my ATS. I'm not worried Anyone tried this and will this effect how the tire monitor functions? BTW, it is my understanding that the pressure on the fronts is lower than the rears in order to reduce over-steering (or is it under-steering).

Submariner409
04-14-13, 01:40 PM
Let's move this up to the ATS forums - much more activity on your vehicle there.

TPMS function and pressure range depends on the original tire pressure recommendations on the driver's door tire rating sticker.

Cisitalia
04-14-13, 07:21 PM
Both BMW and Cadillace ATS have more pressure in the back to invoke more understeer, which is safer for most drivers with average capabilites. I think going to 35/35 is ok, but you won't notice alot less understeer. On the race track I usually have the rears 2 psi lower than the front to dial out some understeer in hopes of getting a more neutral balance. You will be hard pressed to get any amount of oversteer on a stock car. Even race cars don't want oversteering prone setups. Neutral is the desired balance to setup the cars handling.

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I forgot to say, you won't effect the tire monitoring system with that change. There is quite a broad range you have until you effect the low pressure TPMS setpoint.

gfxbt
04-15-13, 11:09 AM
I run mine 37 front 40 rear cold in an attempt to stiffen the car as well as achieve better gas mileage. They get up to about 40/43 while driving (tires indicate a max pressure of 45). I haven't rotated the tires yet (will do at 5,000 miles), so I can't say if I am experiencing increased wear in the center of the tires due to increased pressure. So far I like the set up, but I didn't test the factory settings long enough to have a baseline value for comparison. I am also under the impression that stiffer rear tires is to dial out some over steer. In my experience, to get the back end to really step out you need to get on it hard with the TCS and StabiliTrack off. Mashing the throttle and turning the car (i.e., making a right hand turn out of a parking lot), you can feel the back end start to step out, but the electronics keep everything sorted in short order.

Long story short, you'll be just fine running 35 all around. My guess is you won't even notice a difference.

flycaster
04-15-13, 04:43 PM
...Long story short, you'll be just fine running 35 all around. My guess is you won't even notice a difference.

Interestingly, I really wasn't thinking about controlling for the under- over- steer, I just wanted to get a good ride and get better wear out of the tires. I know that in most cases, the manufacturer generally recommends pressures that will give more of a "comfortable" ride (read softer ride) rather than a performance type ride. Although the ATS rides well, it still has a way to go to give one the feeling of the road as did my E46. Perhaps by bringing my tires to 37#, I will be able to get more wear out of the them (if at 37# the centers don't wear excessively) and also stiffen up the ride a bit???

gfxbt
04-15-13, 06:45 PM
Perhaps by bringing my tires to 37#, I will be able to get more wear out of the them (if at 37# the centers don't wear excessively) and also stiffen up the ride a bit???

That is kind of my goal. I'll let you know in the next month or so when I hit 5,000 miles and rotate the tires if I notice any uneven wear. I'm guessing I won't, as on all of my previous cars I've run 8% or so higher psi than recommended with no problems.

flycaster
04-15-13, 06:49 PM
I await your results. We only do about 4K/year, retired ya' know, so it would take a while for me to know what 37# does, or doesn't do...

aselvan
04-21-13, 12:18 PM
I have a question on the tire pressure applet/app on the dash. My tires are inflated to 32 and 35 for front and rear respectively. I measured it with two different tire pressure tools i.e. digital tire pressure tool and a good old traditional tire pressure tool and both read exactly 32 and 35. However, the applet says 34, 37 (or 36 at times) which is not correct. Does anyone have similar problem or know how to reset the applet so it shows accurate tire pressure?

gfxbt
04-22-13, 10:31 AM
Are you measuring them cold, then looking at the DIC while you are driving (i.e., when the tires are warm)? Or are all three measurements observed during the same time period (e.g., when the car is sitting in the garage, or after a drive)?

flycaster
04-22-13, 11:57 AM
Finally had a chance to see how the tire pressure monitor was working. On a highway ride last night, the tires were reading rather high - high 30's to low 40's. I was truly surprised to see such high readings. Checked the tires with a gauge this morning when they were cold and, indeed, they read around 39psi. I re-adjusted them to 35 fronts and 37 rears, but haven't read them cold with the car's monitor - will do that when wife comes home and tires cool down.

aselvan
04-26-13, 01:30 PM
Are you measuring them cold, then looking at the DIC while you are driving (i.e., when the tires are warm)? Or are all three measurements observed during the same time period (e.g., when the car is sitting in the garage, or after a drive)?

Both readings were "cold tire pressure" readings of course, otherwise, it would not be a valid comparison.