propane and nitrous inject it,extra 200 hp.

Too short a distance
 

You're going too short of a distance to check your mileage, unless you fill the tank up to the exact same spot every time. If you're off by 2 ounces on a fill up, it'll throw all your numbers off on just a 30 mile trip.

Try 100 mile trip or better yet 200 miles. The longer the trip, the more accurate your average will be, if you fill up to the same spot each time.

It is pretty obvious from your first posted statistics that you should only fuel up on Tuesdays. Fuelling on Mondays looks like a real downer and milage killer to me.

My guess is the car is only hung over from the previous weekends on Mondays. Most people want to involve scientificly sound principals. I look at things as the fuel does and just go with the flow.

If you are still not satisfied with the overall fuel milage. Contact an ebay seller. They have figured out ways to really increase milage averages that have eluded most members on our site.

In fact I think I will myself as it sounds like fun. This old dog can learn some new tricks as well. The old ones like jumping through hoops all the time are now wearing.

APC window stickers are proven to add 30hp at the wheels...

...and with unicorn tears you can time travel!

In all seriousness though, I must echo what others have said. The only meaningful mpg numbers are those derived over several tanks and several hundred miles of driving. My 300D averages a solid 25. Best I've ever gotten on a tank was a hair shy of 28, worst was 23.

It sounds like some of the others would be better off sniffing the nitrous that putting in their car !!! :eek::eek::P:P

Consumption varies that much that calcs for less than 1000 miles dont show much !!

hello I pulled this back up for reference. Right now am rebuilding my transmission. I left the rear gear alone still. But am putting a lower gearset in the trans out of a 91 560sel . Its 3.87 opposed to the 3.68 .should give me more pep.I will do my timed runs again once I have got it back in. After I put some.miles on it.

Update on mileage I was getting 26 mpg .in the city. Never on the interstate yet.
Most miles on a tank was 528 I ran it slap out.this is when my AC was broken at the time. But checked it with AC on when.I got it repaired I run out anywhere between 428/460 miles on a tank.