Large naturally aspirated engines are more efficient than small turbos

[tjts1]

Consumer Reports finds small turbo engines don't deliver on fuel economy claims

http://youtu.be/jb1VIp1XR08

[redpoint5]

CR testers are among the strongest of arguments for the link between humans and apes. They consistently get well below EPA figures in their "economy tests", which no doubt consists of mashing the skinny and fat pedals in an alternating fashion until they arrive at their destination. I could not get the horrible economy figures they come up with if I tried.

While I appreciate much of the info CR provides, fuel economy is one that I completely dismiss.

Here is the Cruze figures from "Drivers Like You" on fueleconomy.gov A completely different conclusion can be drawn from this data, and suggests that CR drivers are troglodytes.

[Ryland]

How many of those with turbos are also a bump up in trim level, often leading to the entire vehicle being heavier with wider tires, the 0-60 times of the turbo models also tend to be faster, so as I understand it, it's still possible to get better mileage with a smaller turbo engine, but the rest of the car has to be designed to work with it.

[tjts1]

Originally Posted by redpoint5

CR testers are among the strongest of arguments for the link between humans and apes. They consistently get well below EPA figures in their "economy tests", which no doubt consists of mashing the skinny and fat pedals in an alternating fashion until they arrive at their destination. I could not get the horrible economy figures they come up with if I tried.

While I appreciate much of the info CR provides, fuel economy is one that I completely dismiss.

Here is the Cruze figures from "Drivers Like You" on fueleconomy.gov A completely different conclusion can be drawn from this data, and suggests that CR drivers are troglodytes.

I'm sure you're perfectly capable of beating the CR economy numbers, thats not the point of the test. The point is to replicate real world driving by the average driver who isn't constantly thinking about efficiency. If you're keeping track thats 99% of the people on the road and precisely 0% of people on this forum.

Originally Posted by Ryland

How many of those with turbos are also a bump up in trim level, often leading to the entire vehicle being heavier with wider tires, the 0-60 times of the turbo models also tend to be faster, so as I understand it, it's still possible to get better mileage with a smaller turbo engine, but the rest of the car has to be designed to work with it.

The acceleration numbers they give at the bottom of the article say otherwise. They did make a point that the new Altima is substantially lighter than all of its competitors. I'll take lightness and simplicity over forced induction.

The new small displacement turbo engines are designed to improve the manufacturer's CAFE numbers, not real world fuel economy.

[e*clipse]

Apparently they have no idea how to do real testing.

The data they presented showed hair splitting mpg differences ( 1 or 2 mpg ) while giving no information about the vehicle that the engine was in. Details such as vehicle mass, transmission, drag coefficient, or frontal area would all play a major part in such a test, but they simply lumped all vehicles that had a range of engine displacements into the same category.

[oil pan 4]

A Turbo gasoline engine need 20% fuel to make the same horsepower as a N/A motor.

But on the other hand a turbo diesel gets better fuel milage with a turbo. I have done the N/A to turbo diesel thing and picked up 2mpg on my diesel suburban.

[redpoint5]

Originally Posted by e*clipse

Apparently they have no idea how to do real testing.

Apparently, considering it is way off from both the EPA and the figures reported by drivers in the "real world".

The data they presented showed hair splitting mpg differences ( 1 or 2 mpg ) while giving no information about the vehicle that the engine was in. Details such as vehicle mass, transmission, drag coefficient, or frontal area would all play a major part in such a test, but they simply lumped all vehicles that had a range of engine displacements into the same category.

This further supports my claim that CR testers are unusually hairy, and their conclusions concerning fuel economy should be dismissed. If even 1 other source of information supported their claims, I would take another look. It is apparent though, that they are more concerned with reporting how sporty/powerful every car is than driving a car that is being purchased for efficiency, in an manner that has a modicum of efficiency.

[Frank Lee]

Having seen too many CR reports that conflict with my experience and/or readings, I dismiss ALL OF THEIR CONTENT.

[War_Wagon]

^^ this.

[user removed]

So the Altima did best at 31 MPG, pretty close to fuely's figures for the 30 4 cyls of 31 reported (1 V6) and 0-60 in 8.2 seconds. The wife averaged clsoe to 29 in her Rogue, same engine, I think they did some more tweaks to the CVT.

regards
Mech