2nd Gen Non-Engine/Transmission First Roadtrip..... Wow!

[AUrban]

I drove my 99 on its first road trip (with me & the family in the cab, anyway). I couldn't be any happier. During the first 500 miles of my trip, I was able to keep my mpg's at 23-24 (according to the overhead console). On the return trip, I had a pretty stiff tailwind coming east across Iowa and was able to get 27-28 mpg, again, according to the overhead console. I kept speeds consistently between 64-67 mph. RPM's were approximately 1850-1900.



I was also happy with the diesel prices across Iowa along I80 (I was going from IL to NE and back): $1. 67 for diesel and $1. 71 for soy biodiesel. I filled up with the biodiesel on my return trip.



I'm ecstatic, but are the numbers on the OHC accurate? Unfortunately I didn't have the odometer reset for the trip when I did my first fill-up so I can't verify. I'm heading to Michigan this next weekend, so I'll compare it then.



Overall, the drive was great, the truck was comfortable and most people can't believe I got that good gas mileage with a big ol' pickup.

 

[ndurbin]

Their not to accurate. Let off sometime going down a long hill and watch the OHC numbers go up. Did this in my dads Durango one time saw as high as 40 mpg, which is a joke w/ the 5. 9L V8.



I usually get 10 mpg towing, 15 mpg around town (if I keep my foot out of it), and 20 mpg on the highway. Those are rough averages using the trip odometer. Sometimes their better sometimes their worse (if I let my foot get alil heavy) but their usually around those numbers.

 

[WestTN]

My Trip computer is usually about a half mile per gallon low. At 20 mpg this is 2. 5%. That is not too bad.

As for seeing 40 mpg when letting off, that is probably accurate. If you have two vehicles with one getting 1 mpg and the other getting 100 mpg, you might think your average should be 50 mpg. It isn't though. The actual average would be 1. 99 mpg.

 

[Gary - K7GLD]

My overhead is pretty accurate, after figuring in the oversize tires it came with, which throws miles traveled off by 10%...

 

[Slick]

OHC

Sounds high. First thing is you need to know is what size tires your truck came with and are they currently the same size. I have had three dodges with the OHC and they were all accurate within a half mpg give or take. One of my dodges was a Dakota and I put larger tires on it and had the dealer recalibrate the OHC. I must say they did a very good job on the recalibration, it too was very close to being right on. I measured the circumference of the tire and how many rounds per mile it would turn and the dealer used that number to set the OHC. Don't know if this can be done on the Rams though have not change tire size yet.

 

[schu777]

Throw in a bigger set of injectors and an EZ and that will throw the computer off too... at least on mine it does. During the winter, it was about 4mpg higher than actual... now it's about 6mpg higher than actual.



I know what you mean by the fuel prices... filled up last night at the Flying J in Gretna, NE for $1. 67 - Gas is $2. 05... just can't figure out why the price is so low... not complaining, just wondering why.



Michael

 

[jrobinson2]

In stock trim the overhead on my '99 was about 1 mpg higher than actual mileage.

Also the '99s dont have instant mpg, only average mpg

Jared

 

[AUrban]

After measuring mileage at my last fill, I discovered that my mpg rating from the OHC was about 1. 5mpg "optimistic". That's not too bad and it certainly still makes me happy. The tank of fuel that I was originally happy with measured about 22. 5mpg vs the 24 that the OHC reported (reduced due to some city driving). My last road trip confirmed the same finding at my last fill, 22mpg actual vs 23 on the OHC.



Thanks for all the input.