Fuel Consumption RPM MPH

I think rating fuel consumtion for comperasion purposes can be
misleading.
Wont a 3.5 Liter car will consume less fuel in high speeds compares to
2.5?

Where can I find answers or charts that show fuel consumtion vs speed
for various engine sizes?

Also, what would be the RPM when an automatic gear 3.5 L car is at 75
MPH?
what would be the RPM when an automatic gear 2.5 L car is at 75 MPH?


galsaba

galsaba wrote:
> I think rating fuel consumtion for comperasion purposes can be
> misleading.
> Wont a 3.5 Liter car will consume less fuel in high speeds compares to
> 2.5?
>
> Where can I find answers or charts that show fuel consumtion vs speed
> for various engine sizes?
>
> Also, what would be the RPM when an automatic gear 3.5 L car is at 75
> MPH?
> what would be the RPM when an automatic gear 2.5 L car is at 75 MPH?
>
>
> galsaba
>
the closest you'll probably come to is fueleconomy.gov

and the only rule is there are no rules, because my 5.7L Firebird gets
better real world fuel economy than my co-worker's 2.5L Cougar.

To be more specific -
Toyota Camry V6 or Nissan Altima 3.5.compares to Camry 2.4, or compares
to Nissan Altima 2.5 - all driving same road (same tires, etc.)

75 MPH.


Kevin Mouton wrote:
> galsaba wrote:
> > I think rating fuel consumtion for comperasion purposes can be
> > misleading.
> > Wont a 3.5 Liter car will consume less fuel in high speeds compares to
> > 2.5?
>
> Not necessarily.
>
> >
> > Where can I find answers or charts that show fuel consumtion vs speed
> > for various engine sizes?
>
> Depends on what manufacturer you are talking about. The factory
> engineers have such specs, but it might be hard to find it on the net.
> One thing is for sure. If all else is equal , then the faster you go
> the more fuel you will consume.
>
> >
> > Also, what would be the RPM when an automatic gear 3.5 L car is at 75
> > MPH?
> > what would be the RPM when an automatic gear 2.5 L car is at 75 MPH?
>
> There again, you can't compare apples to oranges. You need to have all
> other variables the same to come up with the sort of figure you are
> talking about. Different cars have different gear ratios in the
> transmission and differential as well as different size tires based on
> which size engine they have in them. All that has to be taken into
> consideration.
>
>
> >
> >
> > galsaba
>
> The engine displacement is one of the things least affecting the total
> fuel efficiency of a vehicle. Many other factors must be taken into
> consideration. The aerodynamics of the vehicle, gear ratios, type of
> emmission controls, weather or not it is naturally asperated, etc., all
> affect fuel economy. Basic engine design plays a lot into how efficient
> the engine will consume fuel as well. It is just not as simple as
> saying a larger engine burns more fuel, because you have to factor in
> the weight of the car wind resistance and all that other stuff to get
> an idea of how efficient the vehicle as a whole will be.
>
> Kevin

galsaba wrote:

> I think rating fuel consumtion for comperasion purposes can be
> misleading.
> Wont a 3.5 Liter car will consume less fuel in high speeds compares to
> 2.5?

It depends. Here are some of Consumer Reports' results:

Toyota Camry 3.5L: 32 MPG highway, 16 MPG city
Toyota Camry 2.4L: 36 MPG highway, 16 MPG city

Chevy Malibu 3.5L: 38 MPG highway, 18 MPG city
Chevy Malibu 2.2L: 38 MPG highway, 16 MPG city

Are you trying to justify to your spouse the extra cost of a V-6?

For what it's worth I drove both the 4 and 6 cylinder version of the
Camry. In my opinion they both were very powerful engines that are
appropriate for that car. If there was a difference in acceleration it
was so small that I could not notice it. If you really concentrate
when the engines are at an idle, it is possible to notice a slight more
vibration from the 4 cylinder than the 6. Otherwise it is a push. I
read somewhere that Toyota developed the V6 for the USA market because
people there like engines with more cylinders. It helps sell cars.

The V6 because it is a bigger engine will probably use a little more
gas at highway speed.

I don't know the V6 is worth the substantial premuim in price, but that
is my opinion.

galsaba wrote:
> To be more specific -
> Toyota Camry V6 or Nissan Altima 3.5.compares to Camry 2.4, or compares
> to Nissan Altima 2.5 - all driving same road (same tires, etc.)
>
> 75 MPH.
>
>
> Kevin Mouton wrote:
> > galsaba wrote:
> > > I think rating fuel consumtion for comperasion purposes can be
> > > misleading.
> > > Wont a 3.5 Liter car will consume less fuel in high speeds compares to
> > > 2.5?
> >
> > Not necessarily.
> >
> > >
> > > Where can I find answers or charts that show fuel consumtion vs speed
> > > for various engine sizes?
> >
> > Depends on what manufacturer you are talking about. The factory
> > engineers have such specs, but it might be hard to find it on the net.
> > One thing is for sure. If all else is equal , then the faster you go
> > the more fuel you will consume.
> >
> > >
> > > Also, what would be the RPM when an automatic gear 3.5 L car is at 75
> > > MPH?
> > > what would be the RPM when an automatic gear 2.5 L car is at 75 MPH?
> >
> > There again, you can't compare apples to oranges. You need to have all
> > other variables the same to come up with the sort of figure you are
> > talking about. Different cars have different gear ratios in the
> > transmission and differential as well as different size tires based on
> > which size engine they have in them. All that has to be taken into
> > consideration.
> >
> >
> > >
> > >
> > > galsaba
> >
> > The engine displacement is one of the things least affecting the total
> > fuel efficiency of a vehicle. Many other factors must be taken into
> > consideration. The aerodynamics of the vehicle, gear ratios, type of
> > emmission controls, weather or not it is naturally asperated, etc., all
> > affect fuel economy. Basic engine design plays a lot into how efficient
> > the engine will consume fuel as well. It is just not as simple as
> > saying a larger engine burns more fuel, because you have to factor in
> > the weight of the car wind resistance and all that other stuff to get
> > an idea of how efficient the vehicle as a whole will be.
> >
> > Kevin