Can some explain "Range" algorithm on VDO?
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Joined: Jun 2003
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From: chicago
2003 E500
Can some explain "Range" algorithm on VDO?
Have about a 25 mile commute home over tollway, expressway and surface streets here in Chicago. Just for kicks, I decided to see how the range feature would react to different driving conditions.
After starting and driving about 1/2 mile to tollway, range was 113 miles with a 1/3 of a tank. Fine. I have driven about 1100 miles since purchase and averaged 17.1 mpg and 25 mph
. Not great for gas mileage. However, for the next 12 miles the range very steadily increased to 177 miles with speeds between 65 and 80 mph. A quick surface short-cut to the expressway and the range had decreased to 135 miles. Again, the range began steadily increasing over the next 10 miles to 154 miles with speeds between 45 and 65. Got off and by the time I had traveled the couple remaining miles range was down to 101 miles.
Now I am not innumerate by any means but this has me stumped. If the car immediately reacted to the speed I was going, the range should have increased quickly upon getting on the tollway, fluctuated slightly with changes and speed, but trended downward. If the car reacted to some period of time or mileage, the short distance should not really have affected an average computation. It seemed to respond very quickly at lower speeds and very slowly at higher speeds. The last few miles I drove before going home were mostly highway - reverse of commute home and lunch. It is a puzzlement.
After starting and driving about 1/2 mile to tollway, range was 113 miles with a 1/3 of a tank. Fine. I have driven about 1100 miles since purchase and averaged 17.1 mpg and 25 mph
. Not great for gas mileage. However, for the next 12 miles the range very steadily increased to 177 miles with speeds between 65 and 80 mph. A quick surface short-cut to the expressway and the range had decreased to 135 miles. Again, the range began steadily increasing over the next 10 miles to 154 miles with speeds between 45 and 65. Got off and by the time I had traveled the couple remaining miles range was down to 101 miles.Now I am not innumerate by any means but this has me stumped. If the car immediately reacted to the speed I was going, the range should have increased quickly upon getting on the tollway, fluctuated slightly with changes and speed, but trended downward. If the car reacted to some period of time or mileage, the short distance should not really have affected an average computation. It seemed to respond very quickly at lower speeds and very slowly at higher speeds. The last few miles I drove before going home were mostly highway - reverse of commute home and lunch. It is a puzzlement.
MBWorld Fanatic!
Joined: Jul 2002
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From: SoCal
MB
it is kind of funky, i dont know how it works though. ours is pretty accurate, and it doesn fluctuate as much sa yours does. its funny, with our 02 camry, it has the same thing, and it fluctuates every snigle second, lol, and when you take your footoff the gas, it just shows 99.9, i guess it doesnt even read 
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2004 E Class
Range
As you drive at highway speeds your "instantaneous" MPG goes up. The range algorithm sees that you are now using less fuel per mile so the range goes up. It assumes that you will contine at that rate and calculates out the range as if you would be geting that higher MPG until the end of the tank. If you go into stop and go driving the reverse is true.
Thats always been my take on the range function.
Thats always been my take on the range function.
Thread Starter
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Joined: Jun 2003
Posts: 110
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From: chicago
2003 E500
Sovren:
I take your point and that is what I thought it should do also. But that is difficult to reconcile with the range slowly drifting up 60 miles over a 12 mile run. I mean it was going up fairly steadily about a mile about every 10 - 15 seconds. Never went down once until I slowed and got off. Hmmm.
I take your point and that is what I thought it should do also. But that is difficult to reconcile with the range slowly drifting up 60 miles over a 12 mile run. I mean it was going up fairly steadily about a mile about every 10 - 15 seconds. Never went down once until I slowed and got off. Hmmm.
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From: Southern California
2007 E350 Sport Package
Being a native Chicagoan I know you don't have a lot of hills, etc. but if you
are going up hill with a low tank I think that also affects your range caclucation. Maybe it sneses less gas in the tank. This si just a guess but I do notice the range dramatically drop when I go up hill especially with a low tank.
It also may just be becuase your MPG sucks when you are going up hill
are going up hill with a low tank I think that also affects your range caclucation. Maybe it sneses less gas in the tank. This si just a guess but I do notice the range dramatically drop when I go up hill especially with a low tank.
It also may just be becuase your MPG sucks when you are going up hill
