I was also thinking why it takes 30 seconds to update....bmw is instant and it has been like that well over 10 years

 

It either averages the data over a 30-sec. period or takes a reading every 30-sec. Just the way they chose to do it. If BMW's is instant, looks like it would be changing like a digital tach and not mean very much.

WayneTN

 

It's reasonably accurate. I've found that it's usually between 0 and 1 mpg off compared to what I get when I calculate it manually (distance traveled / gallons used). It's been off by as much as say 1.5 mpg for me, but that's unusual.

It's a lot better than my Maxima's trip computer which was usually normally at least 2-3 mpg too high.

 

Right, if it was instant it would be useless.

 

I think i'll calc mine by hand next fill up against the computer just for kicks.

 

so is what they say true? once your DTE gets to 0 you have 3 gallons left ?

 

For your information,
Just got my tank filled this morning. My computer was reading that I had averaged 19.5 mpg since last fill.
I added 14.830 gallons after driving 289 miles. Divide that out and it equals 19.4875 mpg - how much more accurate could it be?
I might add - the gauge was not near riding on the empty line - so tank likely does hold 20 gallon.
This was all around-town driving - no on road, but some expressway. AND I DO HAVE FUN AT TIMES!! ( interpreted=zip it in 2nd and 3rd - between lights.
The car only has 1100+ plus miles on it - so dont doubt it will bet 25 on the road soon after some breaking in miles.
A fun car!!