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my friend doubts my CTd.

3517 Views 32 Replies 16 Participants Last post by  TreeCzar
So while on the dodge forum a guy complains he cant get over x mpg out of his turbo z . told him its all in the drive habits and the cursing speed. told them about my personal record run, my buddy frank says BS!!! no way you got 67.3. i told him i have receipts and mileage to verify it. he still says BS. He says i bet you 100$$ and expenses to prove it can do that mpg. now if i lose i pay him 100$... i very rarely travel 1000 miles so doing that long haul is not easy to come by. now i do go to SC every so often and he says lets make a run there to see your mpg... should i do it? Fort Myers to Sc 580 miles... if i pump to lets say 2 psi over factory ( i ran stock on ohio trip) keep the car as empty as i can and keep it at 55mph im sure i can come close but not sure if 100% chance i hit 67.3
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my tires are also a bit lower tread then last run so that may help me with rolling resistance i suppose. im not usually a gambling man but i think the diesel can do it
After all of your evidence, he still doesn't believe you!? What size tires do you have? Reason I ask is I have a LTZ RS, therefore, low profile tires inflated @ 41 lbs cold. Not sure about the diesel. Increasing your tire pressure could help rolling resistance.
My best is 77.5 for 25 miles, but that was on a very specific stretch of PA turnpike with some downhill mixed in. On flat ground at 62 MPH, 60 MPG is definitely doable in ideal conditions, but 67 seems like a bit of a stretch for a full tank or a long run.
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After all of your evidence, he still doesn't believe you!? What size tires do you have? Reason I ask is I have a LTZ RS, therefore, low profile tires inflated @ 41 lbs cold. Not sure about the diesel. Increasing your tire pressure could help rolling resistance.
OEM eco tires for my CTD. i only have 18k hard miles on them.


My best is 77.5 for 25 miles, but that was on a very specific stretch of PA turnpike with some downhill mixed in. On flat ground at 62 MPH, 60 MPG is definitely doable in ideal conditions, but 67 seems like a bit of a stretch for a full tank or a long run.
see 60 i this would be a breeze but as you said 67.3 again is a hard number to hit, repeatable but if i miss the mark 65 mpg i lose 100 lol. now from florida to SC is very flat so not a lot of resistance there. i may also flush my trans before i do a run since im at 20k and im sure the GM oil is at end of its life.
Personally I don't bet so that tactic wouldn't work on me. If he won't take your word for something even with proof then it's up to him to disprove your word. If you made a mistake in your calculations that's one thing, we all make mistakes, but to accuse you of lying! Providing the proof and showing him the results should prove that your word is good and you are a man of integrity. To me that's worth more than the $100.
ersonally I don't bet so that tactic wouldn't work on me. If he won't take your word for something even with proof then it's up to him to disprove your word. If you made a mistake in your calculations that's one thing, we all make mistakes, but to accuse you of lying! Providing the proof and showing him the results should prove that your word is good and you are a man of integrity. To me that's worth more than the $100.
thats the thing i know the car is capable of it and not a over exaggeration. he has been working on cars for ages and never seen close to that number so i can believe the sceptisisum. not many vehicles can do what our CTD does. im not a betting man but im sure i can do 60 no problem
When you get into average MPG that high, it can be really erratic, due to the number of variables involved, even on the same trip. Headwind/tailwind can make a huge difference. In Iowa, I usually saw as much as 1mpg improvement per 2-3mph of tailwind. Similar reductions for headwinds, but perhaps not quite as drastic as with the tailwinds. Or if you had 1 re-gen during your original run and 2 re-gens during your re-do, you could see a reduction in average economy. Higher or lower temperature, different A/C usage, driving in rain, etc. could all cause a different result on your new attempt. So, those variables could make things a bit risky. In the more typical 35-45mpg range, the impacts become less severe, but when you're running on the extreme high end of the mpg range, small things make a bigger impact, just due to the math on the equations involved.
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told him its all in the drive habits and the cursing speed.
My cursing speed is usually pretty high, because the driver ahead of me is probably driving like my grammy when I need to get somewhere. This is good for fuel economy though. :biggrin:

if i pump to lets say 2 psi over factory ( i ran stock on ohio trip) keep the car as empty as i can and keep it at 55mph im sure i can come close but not sure if 100% chance i hit 67.3
What's the max sidewall pressure? Pump it up!
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With one person in the car you will not get that mileage I know I cant cant even close to my max with just one passenger in the car. Thats just what I have seen. You would have to lighten the car by your friends weight. Add the weight of your friend to your car and do a 100 mile run by yourself and see what you can do.
im not a betting man but im sure i can do 60 no problem
Then why bet that you can match your all-time best? That's like betting an Olympic athlete can beat his record on any given attempt. See if he'll take the bet for a slightly lower number. Because right now I'd say your chances are under 50/50 to match all-time best.

One of the factors I'd worry about is what to use to determine when your tank is full. If the pump you use to re-fill clicks off at a slightly higher or lower point, that's going to make a huge difference in the calculations. I'm not sure as your friend will believe the DIC. For a 850 mile run, each 0.13 Gal error is 1 MPG result.
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My best tank as calculated by FUELLY is 57.7. Our car are each a little different. I might be able to get to 60 with minimal stops but 67 would be a push. Best of luck if you try it.
One of the factors I'd worry about is what to use to determine when your tank is full. If the pump you use to re-fill clicks off at a slightly higher or lower point, that's going to make a huge difference in the calculations. I'm not sure as your friend will believe the DIC. For a 850 mile run, each 0.13 Gal error is 1 MPG result.
That's an easy one to address. Just fill it to the rim. It doesn't hurt anything on our diesels. I've been regularly doing that for years now with no issues. The only thing is that it takes about 10 minutes to get that last 3 gallons in.
Brad Herr is getting that kind of mileage, but he took steps to make it happen ( and be more reliable)...
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Brad Herr is getting that kind of mileage, but he took steps to make it happen ( and be more reliable)...
umm i did it with a 100% bone stock CTD i bought at work with 0 miles...the only stepps i took was all driver and route based
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umm i did it with a 100% bone stock CTD i bought at work with 0 miles...the only stepps i took was all driver and route based
I got my 77.5 mpg record with a fully stock vehicle.
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its doable but not very easy. must resist the urge to go faster then 55-60, keep the car light weight, take a extra 10 min to top off fuel neck, keep tires checked before departure and most importantly look ahead and plan best route and see where cars are moving so you dont have to slow down and speed up
I got my 77.5 mpg record with a fully stock vehicle.
Drivers weight makes a huge difference. I loss.
Drivers weight makes a huge difference. I loss.
on flat highway at set speed not as much as youd think but when trying 1100 miles out of a tank every bit of weight lost helps. every 100 lbs lost is like 10hp if i remember
If he's gonna hold you exactly to that fairly extreme figure you gave him, you might lose the bet. This car is new to me so I haven't figured out where the upper limits are here in my driving environment. The best I got was a 25 mile average of 61.7. Half was at 75 mph and the second half was at 65 mph. I ran out of time before I saw the plateau at that speed, but it seems entirely plausible.
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