Scion XD 44.5 mpg NOT hwy!

[Cardinal Grammeter]

I borrowed a friends Scion XD to make a trip from Greensburg to Dubois PA and back. This route is 2-lane state highways, over big hills and deep valleys, through small downs with stop lights and finally to Dubois where a stopped at a couple of shops in town to shop.

The car has the instant MPG readout and I used every tactic I could think of to maximize economy. Yes, 20 mph over crests of hills and 80 mph at the bottom of a valley between two ridges.

What was interesting was that mpg was strictly a function of throttle position.

This really blew me away.

This particular Scion was capable of 50 mpg on the level, however, the throttle position was so minute, maybe 1/16", it was not possible to achieve this with a foot accel pedal.

It was a 5-spd of course.

What I do not understand is why this car had an EPA rating of something like 33 hwy. 40+ on the highway is trivial in this car.

Of course, this is really not impressive since my run of the mill Datsun B210 4dr w/1400 pushrod engine (not even the 1200) got a solid 44 mpg on the PA turnpike from Pittsburgh to NJ.

I recently had a Chevy HHR rental while my Ford Windstar was having its rear axle fixed as per recall (!) and this pig, while having about the same EPA rating as the XD could barely muster 35 mpg on the level. It was an automatic and the instant you touched the gas pedal - even on a slight downhill, the mpg dropped to 35. I experimented going down hills trying to see if I even get an instant readout above 35 and maybe once I got a fleeting 50 mpg for a fraction of a second. (I subsequently turned this pig in and got a Charger 3.5HO which I drove for 4 months while Ford was waiting on parts. The car definitely had E-class Mercedes pedegree but gas milleage was really disappointing. I was getting 15-17 per tank which was quite bad considering it only had 250 HP. (Of course, maybe it weight 4500 lbs, but I think not)

And then there are all those fabulous Honda Civics that have been "riced" and ruined.... So sad.

Regards,
Tom

[SentraSE-R]

Thanks for sharing. Toyota's 1NZ-FE engine is a great fuel miser. The problem most people have is they've always got their right foot planted on the gas pedal. If they'd just set the cruise control at 60 mph, they'd easily beat the EPA. It's not likely when they push 75+ mph.

[Joenavy85]

"and this pig, while having about the same EPA rating as the XD could barely muster 35 mpg on the level. It was an automatic and the instant you touched the gas pedal - even on a slight downhill, the mpg dropped to 35."

-I almost had an explaination, but then i realized you said HHR not SSR, not sure why SSR was stuck in my head. My guess would be the tuning of the engine, IIRC(probably not) the 1NZ-FE is VVT-i, which would make a difference over the HHR engine which isn't even remotely fancy like that

[Joenavy85]

also the difference between 2.2L and 1.5L

[Cardinal Grammeter]

I'm think maybe difference between manual and automatic.

What if it always takes an extra 3HP to turn the automatic? In that case, what mpg would get get from a Scion doing 50mpg on the level and then you demanded another 3hp?

[Daox]

The xD actually uses the 1.8L 1ZZ-FE. Technologically very similar to the 1NZ-FE though.

[Cardinal Grammeter]

BTW, my friend who has the XD has around 100k on it and will trade it in when it starts "nickel and diming" him.

He is thinking about getting a Mini because he needs more room but the nearest dealership is in Pittsburgh which is over 45 min away.

Any other thoughts about a replacement. (He was thinking that the Scion Hamster Car (sorry) is not looking so bad with its new added curves and not so parallel lines - but I don't think he will do it.)

[Rob215]

Originally Posted by Cardinal Grammeter

What I do not understand is why this car had an EPA rating of something like 33 hwy. 40+ on the highway is trivial in this car.

...

Regards,
Tom

Hi,

I just joined this forum and I'm trying to learn as much as I can here. First off, I have a 2012 Scion xD, with a 1.8L 2ZR-FE engine and a 5 speed manual. This engine has dual VVT-i.

How do you get 40+ on the highway? The best I've achieved is 35mpg using cruise control at 65, in 5th gear. I live in South Florida so its flat everywhere. I frequently have to do 30 or 40 mile trips on the highway. What am I doing wrong?

[Flakbadger]

Originally Posted by Rob215

Hi,

I just joined this forum and I'm trying to learn as much as I can here. First off, I have a 2012 Scion xD, with a 1.8L 2ZR-FE engine and a 5 speed manual. This engine has dual VVT-i.

How do you get 40+ on the highway? The best I've achieved is 35mpg using cruise control at 65, in 5th gear. I live in South Florida so its flat everywhere. I frequently have to do 30 or 40 mile trips on the highway. What am I doing wrong?

WARNING: TEMPORARY THREAD HIJACK.

First off, you'll have to slow down. Speaking from personal experience with my Ultragauge, I struggle to break 40MPG when driving 65MPH, but can reach into the mid 50s on level ground when driving 50MPH. As the OP said, MPG is a strict function of gas-pedal pressure.

Second, are you using any sort of Scangauge or Ultragauge? Does your car have an instantaneous fuel display? If the answer is "no," then you'll have to take my word for it; my car (and all cars) get utterly abysmal MPG when accelerating. Mine gets between 5-12 MPG when accelerating through first and second gear, even if I'm pretty gentle with the pedal. If my all-highway trip was short, that acceleration would affect my overall trip MPG pretty severely.

Finally, hills are actually beneficial to MPG, contrary to popular belief. I can coast down hills in 5th gear and the injectors cut off--meaning infinite MPG--if they are steep enough. Even if they are mild, the downhill slope allows my vehicle to reach into the 70MPG range with light pedal pressure, and 300MPG in neutral.

Your all-flat-ground, 65MPH cruise-control MPG is not that surprising in light of these facts. Try driving 55 and see what that does for you, and if you want to get really serious, get a fuel gauge. It does amazing things for your understanding of MPG.

~Matt

[Cardinal Grammeter]

Rob215,

First, his is a much older XD (I just tried to call him and I am very sure the car is <2010.)

Note that he did not get uber mileage until he had 10-20k miles on the engine. Then, it got the big numbers.

Then is the possibility that he got a car that just so happened to have a special test engine. While never admitted to, some cars get engines that radically better gas mileage than the published specs. In particular the GM 3.8 - so of these made it to the road with lean burn tables already in their ECU and in some cases enabled.

I told him, he should keep his XD until the wheels literally fall off because I would bet money that he will get significantly poorer gas mileage with a new replacement that claims better. Remember, his car is EPA spec'd hwy at something like 34 mpg and people usually get less!

On level road, I was clearly getting 50 mpg but it was physically impossible to control the throttle position since it required maybe 1/16" at the pedal. The cruise would drift and pump resulting in less mpg.

One theory could be fly by wire engines. Is the 2011 HHR FBW? It could be that a FBW system would not attempt to maintain a "1/16" " throttle position since this is of the order of the clearance stackup between the pedal and the throttle plates. If FBW starts at "1/8" " you will never see 50 mpg. Its also possible that running and engine with just a crack in the throttle plates results in increased emissions for some reason maybe related to boundary layer flow. So to keep the EPA happy, they program that out. But that is wild speculation on my part. Who knows, maybe he got a special engine with lean burn tables enabled?