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Glaird
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729 Posts
Forgive me for not using the absolute exact technical terms. My understanding is that fuel consumption is purely related to the required horsepower needed to move a vehicle at a certain speed. That requirement will come primarily from the CX (aerodynamic coefficient) and the weight.

Under this premise, the fuel consumption of the V8 and the I6 should be very similar when traveling at the same exact constant speed. There are other factors of course, like wind, incline or tire size, but I am going to assume that those are equivalent between your case and mine.
Theoretically yes. But like introductory physics class you are talking about the mythical frictionless surface, non-existent wind resistance, etc. An 8 cylinder engine has 30%, approximately, more parts moving across surfaces that do have a certain amount of friction. Combine that with combustion inefficiencies, and you will probably come up with most of the differences in mpg's, between an I-6 & V8.
 

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What was that?
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Theoretically yes. But like introductory physics class you are talking about the mythical frictionless surface, non-existent wind resistance, etc. An 8 cylinder engine has 30%, approximately, more parts moving across surfaces that do have a certain amount of friction. Combine that with combustion inefficiencies, and you will probably come up with most of the differences in mpg's, between an I-6 & V8.

Do you mean that an engine with 8 cylinders will consume significantly more fuel than a 6 cylinder one of comparable technology/efficiency, in order to produce the same HP?

I do believe there is a significant factor related to tire size, and some V8’s with M-Sport pkg have massively large tires with large contact patches...


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Glaird
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729 Posts
Do you mean that an engine with 8 cylinders will consume significantly more fuel than a 6 cylinder one of comparable technology/efficiency, in order to produce the same HP?

I do believe there is a significant factor related to tire size, and some V8’s with M-Sport pkg have massively large tires with large contact patches...
I was speaking specifically of the apparent anomaly between a 6 cylinder and 8 cylinder engine, allegedly producing the same amount of power. Of course, aerodynamics, rolling resistance, real RPM of the output shaft to achieve the same speed, etc. are all going to make a difference between cars.
I did forget another important factor, the 3rd law of thermodynamics. With every conversion of energy, that is per cylinder, there is a net loss to entropy. 30% more cylinders means 30% more conversion loss, for whatever amount that is.
 

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This type of driving (maximizing range) runs in my DNA. We always factored total range among the top purchase decision drivers when getting a new car. My dad has now taken it to the extreme with his last car purchase: He now has a VW Amarok with the 2L 16V Twin Turbo Diesel and added a 135 liter tank in the bed of the pickup - combined he has ~200 liters of diesel, for a highway driving range of ~2800 kilometers. There's no bladder in this planet that can out-last that.


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The funny thing is I drive my cars spiritedly and like I stole them. I don't drive them for mileage or to maximize tank range. Diesel vehicles have bladder busting tank range. The tank capacity is sized for the gas guzzler version(s) of the same car to give them a reasonable tank range. On a long trip I always have to stop to P long before the car needs to stop for fuel.

One nice thing about driving diesel vehicles is they still get very close to their published fuel economy numbers while being driven hard. There is less of a "play time" penalty involved and no need to drive it like a Prius the rest of the time. There is no "training the driver" involved to get the published fuel economy numbers. Just DRIVE IT! :)
 

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May sound silly but... why take the risk of going to jail for driving at 100mph and being locked up amidst covid 19? ***x1f937;***x200d;***x2642;***xfe0f; The cost of a speeding ticket far exceeds a couple miles per gallon.
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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Thanks for the warning about Minnesota, I***8217;ll have to look into that before we visit the Lake Woebegon Trails between St. Joseph and Osakis. We***8217;re planning to ride there later this year - eight hours west of us at the speed limits.

If you will drive in any major metropolitan area, except maybe Murkee, you***8217;ll see that few are jailed for speeding 100 MPH, more likely for contempt of cop. I regularly see others at 100+ around Chicago on the expressway, Atlanta on I-285 (that can***8217;t be the speed limit, no one can do 285!) and all up and down I-95. On I-95 near Federal Law Enforcement Training Center - FLEa Tech - you will get an extra look by trainees for driving less that the local flow of traffic.

Finally, why bother with the expense of a BMW, a Toyota is less noticeable?
 

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Discussion Starter #28
Thanks for the warning about Minnesota, I'll have to look into that before we visit the Lake Woebegon Trails between St. Joseph and Osakis. We're planning to ride there later this year - eight hours west of us at the speed limits.

If you will drive in any major metropolitan area, except maybe Murkee, you'll see that few are jailed for speeding 100 MPH, more likely for contempt of cop. I regularly see others at 100+ around Chicago on the expressway, Atlanta on I-285 (that can't be the speed limit, no one can do 285!) and all up and down I-95. On I-95 near Federal Law Enforcement Training Center - FLEa Tech - you will get an extra look by trainees for driving less that the local flow of traffic.

Finally, why bother with the expense of a BMW, a Toyota is less noticeable?
I once did a road trip from Portland OR to San Francisco, and I was driving my Toyota Camry, well over 100mph, most of the interstate on a weekend. No cops bothered me.
 

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I once did a road trip from Portland OR to San Francisco, and I was driving my Toyota Camry, well over 100mph, most of the interstate on a weekend. No cops bothered me.

Yeah! Corporate/fleet cars are best for undercover speeding, especially if painted anything other than arrest-me-red...

I did Fayetteville, AR to Moab, UT in my booooring silver Ford Taurus company car. Three drivers, non-stop, averaged 98 mph over 1,150 miles. I was very respectful of posted speeds within city limits, and flat out on open stretches of interstate. I did get passed by a cop probably doing 125+ somewhere near the state limit between Kansas and Colorado.


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Discussion Starter #30
Driving a full-size sedan over 100mph is much safer then doing it with a large SUV like X5. Sedan is more planted and stable at high speeds and less chance of a roll-over.
 

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Thanks for the warning about Minnesota, I'll have to look into that before we visit the Lake Woebegon Trails between St. Joseph and Osakis. We're planning to ride there later this year - eight hours west of us at the speed limits.

If you will drive in any major metropolitan area, except maybe Murkee, you'll see that few are jailed for speeding 100 MPH, more likely for contempt of cop. I regularly see others at 100+ around Chicago on the expressway, Atlanta on I-285 (that can't be the speed limit, no one can do 285!) and all up and down I-95. On I-95 near Federal Law Enforcement Training Center - FLEa Tech - you will get an extra look by trainees for driving less that the local flow of traffic.

Finally, why bother with the expense of a BMW, a Toyota is less noticeable?
Not to be a curmudgeon about speeding, just don***8217;t like to take the risk of lockup!
 
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