From: Scott Dorsey on
Jesse <sumin(a)telus.net> wrote:
>Perhaps I should clarift my situation. The discussion followed an
>attempt to select a car for my daughter, she prefers good milage. I
>drove both cars on the same road, at the same speed and observed at 65
>MPH the 4 cyl at 2700 rpm and the 6 cyl at 2200 rpm. The question was
>which car should get the best fuel economy at these conditions.
>Neither myfriend or I know.

Nope. Given the information you've provided, nobody can know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
From: Tegger on
Jesse <sumin(a)telus.net> wrote in
news:05n936t99qcilrpusdahkbggns1l0dtug6(a)4ax.com:

> On Tue, 6 Jul 2010 12:14:52 +0000 (UTC), Tegger <invalid(a)invalid.inv>
> wrote:
>
>>Jesse <sumin(a)telus.net> wrote in
>>news:ib95361v126e4f9msaaovpehaaa7o2i9eh@ 4ax.com:
>>
>>> I had a discussion with a pal about comparing vehicle fuel economy.
>>> Would a 6 Cylinder at 65 MPH showing 2200 RPM use less fuel than a 4
>>> cylinder showing 2600 RPM at 65 MPH?
>>>
>>
>>
>>I think the question is impossible to answer as a generic thing; there
>>are too many variables.
>>
>>What are the characteristics of each engine and each car? How much
>>power is being created by each engine, and where in their rev-range?
>>How heavy is each car? How much wind-resistance has each car? How much
>>throttle-opening is required to maintain speed in each car?
>
> Perhaps I should clarift my situation. The discussion followed an
> attempt to select a car for my daughter, she prefers good milage. I
> drove both cars on the same road, at the same speed and observed at 65
> MPH the 4 cyl at 2700 rpm and the 6 cyl at 2200 rpm. The question was
> which car should get the best fuel economy at these conditions.
> Neither myfriend or I know.
>


And neither does anybody else.

As I and several others have already pointed out, there are way too many
variables present to be able to give a black-and-white answer to your
extremely general question. Plus you've provided zero information about the
cars you've driven.

So, what are the particular cars in question? www.fueleconomy.gov
has pretty accurate figures for all US-market vehicles. You may wish to
check there.

--
Tegger
From: Tegger on
kludge(a)panix.com (Scott Dorsey) wrote in news:i12p32$134$1
@panix2.panix.com:

> Jesse <sumin(a)telus.net> wrote:
>>Perhaps I should clarift my situation. The discussion followed an
>>attempt to select a car for my daughter, she prefers good milage. I
>>drove both cars on the same road, at the same speed and observed at 65
>>MPH the 4 cyl at 2700 rpm and the 6 cyl at 2200 rpm. The question was
>>which car should get the best fuel economy at these conditions.
>>Neither myfriend or I know.
>
> Nope. Given the information you've provided, nobody can know.



A bicycle will return superlative gas-mileage, I think.


--
Tegger
From: TE Cheah on
> Would a 6 Cylinder at 65 MPH showing 2200 RPM use less fuel than a 4
> cylinder showing 2600 RPM at 65 MPH?

If this 6 cyl has 3 litre, then 3 x 4/6 x 26/22 = 2363 cc, so if this
4 cyl has >2363cc, both have same fuel ratio @ these rpm, no
super / turbo charging, then theoretically this 4 cyl will use more.


From: TE Cheah on
> if this 4 cyl has >2363cc, both have same fuel ratio @ these rpm, no
> super / turbo charging, then theoretically this 4 cyl will use more.

I revise my calcn to 3 x 22/26 = 2538 cc.