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RE: Buying 2015 isx 2350 234k miles high hours - FnG92 - 10-05-2021

Is there a mathematical way to explain driving 63 instead of 65 or 68 (if legal) in regards to fuel savings? Let's say 1 more mile per gal and multiply by let's say 2k miles a week or something minus the same mileage but at 68 to see the cost of the extra mph in a theoretical breakdown of costs.


RE: Buying 2015 isx 2350 234k miles high hours - tree98 - 10-05-2021

You could have it tuned to be more lenient so the system operates but won't leave you stranded because of an emissions related derate or use as much EGR gas (less soot inside your engine) also won't use nearly as much DEF.


RE: Buying 2015 isx 2350 234k miles high hours - Rawze - 10-05-2021

maybe this helps.
http://rawze.com/forums/showthread.php?tid=113&pid=627#pid627


RE: Buying 2015 isx 2350 234k miles high hours - FnG92 - 10-05-2021

Yes I read that earlier! I need to get sensors (not sure which ones) I'm going to need to buy tires so I don't know what to buy and after that I would like to try getting it tuned the way you mention in the linked post.


RE: Buying 2015 isx 2350 234k miles high hours - Fast Hedgehog - 10-17-2021

(10-05-2021 )FnG92 Wrote:  Is there a mathematical way to explain driving 63 instead of 65 or 68 (if legal) in regards to fuel savings? Let's say 1 more mile per gal and multiply by let's say 2k miles a week or something minus the same mileage but at 68 to see the cost of the extra mph in a theoretical breakdown of costs.

Simply put, there is no simple formula that calculates that because road environments are all unique. Charging 68 up and down a mountain will have vastly different dominating factors in efficiency calculations than driving on a flat road. Local driver (slower average speed) vs long haul (higher average speed). There are tons and tons of variables that could change dependent on tons and tons of situational variables. Driving on a new road vs bumpy road will change that calculation, road temperature, ambient air temp, what tires are used, what wheel lubrication is used, wind direction.... the list goes on and on.

The best way to do this is not to model an equation to calculate efficiency, but to model an equation based on your efficiency history. Keep a fuel notebook where you note mpg, type of driving, weight, idle time, ect and you will be able to find a trend for your situation.

Simple post on the aerodynamic forces: https://physics.stackexchange.com/questions/81001/how-can-you-calculate-air-resistances-at-different-speeds
Post with more derivations of equations: https://physics.stackexchange.com/questions/163788/how-much-of-the-energy-of-a-car-is-required-for-overcoming-air-resistance

And that's just explaining power output needed from the truck. Now you'd have to do a ton more calculations on the efficiency of the process of getting the BTUs contained in Diesel converted to the torque at wheels via the engine, drive train, other parasitic loads.


RE: Buying 2015 isx 2350 234k miles high hours - Rawze - 10-18-2021

Even on an aero truck, slowing down always wins whenever fuel prices are more than $2 / per gallon. It is as simple as that. For a square nose truck fuel prices would have to drop below $1.60/gallon for most operations.

People try like she#lll to justify driving that 65 - 75+ whatever the speed limit is + a few mph.. but they always pay dearly for it.. plain and simple.

You want to make more money in trucking.. SLOW THE H#ELL DOWN!!!. SIMPLE AS THAT!

I also will not let this become an argument on my forum.. take it over to social madai if you disagree.. It has been beat to death on every truck forum on the planet already.

* I have never met a O/O that drives 60 mph or below that did not make a very decent damn moneys .. but I have met hundreds of drivers who have nothing but problems, and spend way more than they should in everything they do.. them turn around and complain that freight rates are too low ... simply because they have not enough discipline to slow down and make an actual paycheck+ plus stop letting the roads beat the s$it out of their equipment due to "going highway speeds" all the time .. they seem to not be able to properly manage their #1 top of all expenses like a hawk ... FUEL!@ whatsoever.

it is not an argument for debate.. it is fact and anyone who disagrees can go take that argument over to some other place.. it does not belong here!@.