3 questions

I have an 04 v6 4runner. I have three questions that I hope someone out there can help me with:

1 Does anyone change their own oil? Do I have to take off the skidplate or is there a way to get that disc off that covers the oil pan?

2 My truck has 17inch wheels. From the factory. I have tested it three times using interstate markers. It consistently come up 3 tenths short on the odometer for every 5 miles. Doesnt sound like much but could make a big difference over a few years. Also would make the mpg calculation incorrect. Has anyone else checked this?

3 The avg mpg on the multi info display is way off according to my manual calculations. Can Toyota fix this or should I just turn it off? I paid for it so I would like for it to work.

2. If you are talking about the trip odometer, then this is normal. They are consistenly off. However, the vehicle odometer should be very close.

3. Get some data to support your assertion and bring it in to Toyota. For miles traveled, use mileage markers on the highway. This readout should be close. I guess it depends on what you call "way off". If you used the trip odometer to validate the readings, then recheck with a more accurate measure of distance.