[Manan^BMW]

Chaps,

So I was playing around with the OBC. Also, went through some other posts about OBC. But somethings are still not very clear.

MPG, Miles to Empty, Avg. MPH: How accurate is it? Is the 5 mpg a built in error? I did some primary calculations based on how much my car is sipping and the OBC seems to be very close.

I dont want to take additional portal space so I will just post other questions right here, if you dont mind.

Q1. What exact model is my car? Has alarm (with the little l.e.d near the lighter), has cruise control, OBC, sunroof (if it helps), has food lamps ( not OEM's though), side skirts.

Q2. Is it alright if I unplug the old battery and replace it with a new one? How will it affect the OBC and other electronics?

Q3. Fuel tank capacity? Is it 13.7 + 2.1 reserve = 15.8?

Q4. Probably a very subjective question but - a. Is it alright to do a 1800 miles round trip from Pullman to SFO during Santa time in a ti which has 230k on it?
b. If yes, what are the possible things to watch out for.
c. Is it advisable to buy a GPS? Which one is the best of the lot in your experience up till $200?


Thanks very much in advance.



Manan