New fuel economy ratings

[Even Steven]

Okay, so I know that none of us here purchased our 4Runners for fuel economy, but I noticed something interesting while looking at the new 2008 EPA fuel economy ratings.

Here are the fuel economy ratings (city/highway):

2008

V6 4wd: 16/20
V8 4wd: 14/17

These new "real world" numbers are supposed to reflect the conditions that we encounter on our roads. It seems to me that there is more than a 1 mpg difference between the V6 & V8 engines. According to the EPA, the V6 engine should get about 18% better fuel economy on the highway than the V8. This is much more significant than the usual "my V8 gets only 1 mpg less than the V6" posts I see here so often.

Now here's the real surprise:

Compare the figures for each engine in both 2wd and 4wd:

2008

V6 2wd: 16/21
V6 4wd: 16/20

V8 2wd: 15/19
V8 4wd: 14/17

Notice that the numbers are almost identical for the 2wd and 4wd V6 models? The fuel economy penalty for the 4wd is just 1 mpg on the highway, and no change in the city. On the other hand, the V8 has a higher penalty, due to its inability to run in 2wd mode. I don't understand why Toyota wouldn't drop the full-time 4wd system on the V8 and allow the use of 2wd like the V6 models.

BTW, this post is not intended to start a V6 & V8 fuel economy war, but rather to take a look at the real differences between the economy and drivetrain configurations of each choice.

 

[JosephD05]

Okay, so I know that none of us here purchased our 4Runners for fuel economy, but I noticed something interesting while looking at the new 2008 EPA fuel economy ratings.

Here are the fuel economy ratings (city/highway):

2008

V6 4wd: 16/20
V8 4wd: 14/17

These new "real world" numbers are supposed to reflect the conditions that we encounter on our roads. It seems to me that there is more than a 1 mpg difference between the V6 & V8 engines. According to the EPA, the V6 engine should get about 18% better fuel economy on the highway than the V8. This is much more significant than the usual "my V8 gets only 1 mpg less than the V6" posts I see here so often.

Now here's the real surprise:

Compare the figures for each engine in both 2wd and 4wd:

2008

V6 2wd: 16/21
V6 4wd: 16/20

V8 2wd: 15/19
V8 4wd: 14/17

Notice that the numbers are almost identical for the 2wd and 4wd V6 models? The fuel economy penalty for the 4wd is just 1 mpg on the highway, and no change in the city. On the other hand, the V8 has a higher penalty, due to its inability to run in 2wd mode. I don't understand why Toyota wouldn't drop the full-time 4wd system on the V8 and allow the use of 2wd like the V6 models.

BTW, this post is not intended to start a V6 & V8 fuel economy war, but rather to take a look at the real differences between the economy and drivetrain configurations of each choice.

I would think the reason the V6 2wd and 4wd models are almost identical is because they can leave their truck in 2wd while v8 owners cannot.

 

[Even Steven]

Yeah, that's exactly what I said.

 

[Falls]

REAL WORLD NUMBERS.....lol. I always think those numbers are such BS, but they got to put something on the sticker, they NEVER will and can NEVER reflect , road conditions , tire pressure and tread and size , peoples personal driving habits , weather conditions ,ect...... and can never reflect that the v6 has to work harder than the v8 and probably offsets the very minimal addition of milage you MIGHT get by having a v6 and a 2wd selector , which also still provides drag on the front shafts ect. which are still turning , but not driving.

A 2wd model is a different story though , because of not having all the 4wd stuff to drag along , so can see that milage being better.

Interesting observation though.

 

[Cornfed]

REAL WORLD NUMBERS.....lol. I always think those numbers are such BS, but they got to put something on the sticker, they NEVER will and can NEVER reflect , road conditions , tire pressure and tread and size , peoples personal driving habits , weather conditions ,ect...... and can never reflect that the v6 has to work harder than the v8 and probably offsets the very minimal addition of milage you MIGHT get by having a v6 and a 2wd selector , which also still provides drag on the front shafts ect. which are still turning , but not driving.

A 2wd model is a different story though , because of not having all the 4wd stuff to drag along , so can see that milage being better.

Interesting observation though.

I'm going to have to disagree greatly on your 2wd/4wd selector theory. I can cruise along at 55 to 65 mph and switch mine into 4wd and watch the mpg readout begin to drop, it usually drops around 2 mpg on any trip. It can't be terrain because here in the Florida Keys we don't have any, its all flat.
It also goes the other way, as soon as I switch back to 2wd it starts to go back up within a mile or so. I had a Mits Montero with the original active-trac and it lost mileage also when using 4wd but it never got mileage as good as the T4R despite having 90hp less. Damn I love technology!

 

[Even Steven]

REAL WORLD NUMBERS.....lol. I always think those numbers are such BS, but they got to put something on the sticker, they NEVER will and can NEVER reflect , road conditions , tire pressure and tread and size , peoples personal driving habits , weather conditions ,ect.....

Just in case you didn't know, the EPA revised the way they test fuel economy standards because their old test parameters were very unrealistic. As a result, the majority of vehicles dropped in their fuel economy ratings. Of course actual fuel economy varies by the many variables you mentioned, but as far as testing is concerned, it is a good way to judge two vehicles operated under identical conditions.

That said, the V8 model did suffer a bigger drop under the new testing guidelines than the V6.

 

[Even Steven]

..... and can never reflect that the v6 has to work harder than the v8 and probably offsets the very minimal addition of milage you MIGHT get by having a v6 and a 2wd selector , which also still provides drag on the front shafts ect. which are still turning , but not driving.

Do you know that normally aspirated engines operate most efficiently at full throttle? Sure, you can say it's working harder, but it is also allowing the most volume and most even distribution of induction air. Operating your engine at part throttle restricts air flow and reduces efficiency. Therefore, a V6 engine that is "working harder" is also working more efficiently.

BTW, the front driveshaft doesn't turn in 2wd mode. I'm not sure where you got that idea....

 

[jwa898]

This is very interesting, and although the new EPA standards aren't perfect they are much more realistic than the previous test. I wonder if Toyota will see a significant drop in sales of the V8 since gas prices are rising and you can no longer look at it as only a 1mpg difference.

 

[Falls]

BTW, the front driveshaft doesn't turn in 2wd mode. I'm not sure where you got that idea....

Yes it does , your front half shafts and drive shaft all turn when you are driving they are not engaged to the transfer case. The only way that would not turn as you drive along is if you had electronic or manual locking front hubs. The 4R always has hubs engaged and the selector puts it into the "auto" mode ( if you want to call it that ) where its connected to the tcase and varies power as where its needed. You have to remember that the only thing the switch does and the center diff. lock switch does all comes from the center tcase.

 

[Falls]

Do you know that normally aspirated engines operate most efficiently at full throttle? Sure, you can say it's working harder, but it is also allowing the most volume and most even distribution of induction air. Operating your engine at part throttle restricts air flow and reduces efficiency. Therefore, a V6 engine that is "working harder" is also working more efficiently.

Well from someone who has both naturally and forced induction motors , I really doubt that statement. Pushing a head wind up a highway and having the 6 working harder is in no way going to result in more efficient fuel milage.

 

[Thai]

REAL WORLD NUMBERS.....lol. I always think those numbers are such BS, but they got to put something on the sticker, they NEVER will and can NEVER reflect , road conditions , tire pressure and tread and size , peoples personal driving habits , weather conditions ,ect......

Falls, the new EPA numbers very closely reflect real-world driving by the average consumer. Obviously, the Fast-&-Furious crowd will get different numbers...and vice versa for the grandmas on the road. For example, the Corolla & G500 numbers are pretty spot on for my driving...same goes for my Sienna.

Although these numbers may not reflect YOUR driving, it is still damn accurate as a comparison tool. Since both engines (V6 & V8) were tested under the same conditions, by the same drivers (if any), by the same lab, by the same tester/engineers, etc., these numbers are PERFECT for comparisons between different engines/powertrains. This is MUCH BETTER than asking two 4runner owners (one V6, one V8) on this forum about their MPG numbers because there are way too many variables to make such numbers valid. In other words, EPA gives a STANDARD that you can use to compare different engines/powertrains. (The previous "inaccurate" version could be used in a similar way, but too many people fail to see this as a tool and complain about it's inaccurate real world values.)

So, yes, the above EPA numbers is a great way to see the differences between the powertrains on the 4runner...and probably, the ONLY valid argument for one way or another.

 

[Falls]

This is very interesting, and although the new EPA standards aren't perfect they are much more realistic than the previous test. I wonder if Toyota will see a significant drop in sales of the V8 since gas prices are rising and you can no longer look at it as only a 1mpg difference.

The milage still may not be that different because of situations. I cant exactly remember what my window sticker said on my V8. I think it was 16/20 and if I remember correctly the V6 was rated at 17/21. The lowest I personally have EVER had was during winter blended fuel ( another variable in fuel EPA estimates) which is always a little lower has been 15.5 in the city. I drive aggressive and off road when I can . When pulling a few thousand pounds or driving in deep snow storms being the exception or 4lo expedition's.

I'm never going to argue a v6/v8 gas debate , they are simply so close with so many variables involved there is no way to predict that accurately , close yes , but were already within 1-2 mpg.
I've driven both v6/v8 and both are excellent .

v8/v6 are really weird at dealers from what I see. I have 2 dealers that I visit their lots damn near every weekend , just to nose around. The one close by my house had most all v6 for the last 2 months while the other dealer had most all v8's , now since the last shipment of trucks have come in it seems like they flipped flopped who has mostly v6's and who has mostly v8's I dont know the in's and out's on how they order , but I've noticed this trend since in I started looking at them.

As gas climbs the consumer will deff. gravitate to the v6 trying to save as much fuel as possible. Its a good thing to watch your money I will never knock that . They would probably be surprised over the length of time they own the vehicle how little money they do save. I figured out with my hi milage driving and the 1 mpg difference on my 06 window sticker and driving 2500 per month it was like $20.00-30.00 a month , not huge but everything counts. The v8 also costs more money at the pump but don't forget about the option package alone ( cant remember cost ) , but them add in the recommended timing belt /chain replacement , plug replacement on the v6 , and how does that fair out ???? not sure but no matter what it all costs us good money to drive these fine vehicles no matter what motor.

Bottom line get what you like and take the window sticker as a guess and not cast in stone. A friend who is a service writer told me that you would not believe how many people come in with their gas milage log or even off their 1st tank of gas and wonder why they are not hitting the sticker numbers. Now our generation is pretty acceptable , but its usually the older folks. ( like my mom & dad....)

 

[Falls]

Falls, the new EPA numbers very closely reflect real-world driving by the average consumer. Obviously, the Fast-&-Furious crowd will get different numbers...and vice versa for the grandmas on the road. For example, the Corolla & G500 numbers are pretty spot on for my driving...same goes for my Sienna.

Although these numbers may not reflect YOUR driving, it is still damn accurate as a comparison tool. Since both engines (V6 & V8) were tested under the same conditions, by the same drivers (if any), by the same lab, by the same tester/engineers, etc., these numbers are PERFECT for comparisons between different engines/powertrains. This is MUCH BETTER than asking two 4runner owners (one V6, one V8) on this forum about their MPG numbers because there are way too many variables to make such numbers valid. In other words, EPA gives a STANDARD that you can use to compare different engines/powertrains. (The previous "inaccurate" version could be used in a similar way, but too many people fail to see this as a tool and complain about it's inaccurate real world values.)

So, yes, the above EPA numbers is a great way to see the differences between the powertrains on the 4runner...and probably, the ONLY valid argument for one way or another.

No doubt it's good for comparison for buyers. My orig. gas milage ratings have been right on from day 1. Also my driving style if aggressive but not like the F&F crowd . I'm safe and smart. Although I do have to drive a little harder for my "job" at times. ( not often but it does happen )

Why was the EPA letting them post the higher milage to begin with ? Was it just the automakers just BS'n the consumers ? If thats true .....sad!

 

[Thai]

Why was the EPA letting them post the higher milage to begin with ? Was it just the automakers just BS'n the consumers ? If thats true .....sad!

See: http://www.toyota-4runner.org/showthread.php?s=&threadid=25859&highlight=epa+fuel+economy

 

[Even Steven]

Yes it does , your front half shafts and drive shaft all turn when you are driving they are not engaged to the transfer case. The only way that would not turn as you drive along is if you had electronic or manual locking front hubs. The 4R always has hubs engaged and the selector puts it into the "auto" mode ( if you want to call it that ) where its connected to the tcase and varies power as where its needed. You have to remember that the only thing the switch does and the center diff. lock switch does all comes from the center tcase.

The front driveshaft doesn't move in 2wd mode. I know for a fact this is true. Sorry, but you're wrong on this one.

 

[Even Steven]

Well from someone who has both naturally and forced induction motors , I really doubt that statement. Pushing a head wind up a highway and having the 6 working harder is in no way going to result in more efficient fuel milage.

It's true...look it up. Do you know that combustion engines are VERY inefficient? Most of their energy is wasted as heat.

Did you know that airplane and boat engines typically run at full throttle (and are designed to run that way) the majority of time? Did you ever wonder why?

EDIT: I added the link below, which is a great read if you want to understand why a smaller engine working "harder" is more efficient than a larger engine working "easier"

http://mb-soft.com/public2/engine.html

 

[Falls]

It's true...look it up. Do you know that combustion engines are VERY inefficient? Most of their energy is wasted as heat.

Did you know that airplane and boat engines typically run at full throttle (and are designed to run that way) the majority of time? Did you ever wonder why?

EDIT: I added the link below, which is a great read if you want to understand why a smaller engine working "harder" is more efficient than a larger engine working "easier"

http://mb-soft.com/public2/engine.html

I'm always up for learning .... thanks

 

[sharp4runr]

Now these numbers could be lying a bit unless we know how the test were taken:

Compare the figures for each engine in both 2wd and 4wd:

2008

V6 2wd: 16/21
V6 4wd: 16/20

V8 2wd: 15/19
V8 4wd: 14/17

With the 4WD V6 model, was the study taken while the vehicle was in 4WD? Or was it a 4WD vehicle drive in 2WD? Also from my real world experience, I've driven my 4WD V6 in 4HI and the mileage difference was negligeble compared to running it in 2HI. I think the reason is that even if I'm only running in 2HI, I'm still carrying around the weight of the 4WD components. Also I as I understand it, the V8 model is heavier than the V6. During stop and go driving, the extra weight would explain the MPG penalty.

Feel free to check my mileage numbers in my signature. Most of my driving is in DC Metro traffic so that explains the lower mileage but it still is inline with the EPA estimates for the most part.

 

[dcon]

Hello folks,
Attached is some info backing up Even Steven's statement regarding the front shaft disconnecting in 2WD mode. btw - this is my first post. Great forum!

 

[Even Steven]

Hello folks,
Attached is some info backing up Even Steven's statement regarding the front shaft disconnecting in 2WD mode. btw - this is my first post. Great forum!

Thanks for the link backing up my statement. But I knew the front driveshaft wasn't driven while in 2wd because I've turned it by hand to get to the zerks while greasing it. I remember one time doing it while I had left it in 4wd, and I obviously couldn't turn it!