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silbeej

macrumors 6502a
Original poster
Feb 3, 2007
797
0
Anyone know why cars sold in countries like the UK get so much better fuel economy than those sold in the US? Even after i convert MPG from imperial gallons to US gallons, the MPG is still off the chart compared to US sold vehicles. Any thoughts?
 
I do know the methodology as to how they determine fuel economy (e.g. rate,speed, fuel blend, etc) makes a difference. I'd bet that might be part of the reason.
 
More diesels, and the motors tend to be smaller and more fuel efficient.

In the US, we have a hankering for bigger motors with more HP.

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We like big cars with 300-400 HP and 14 mpg, not the little fuel miser with 70-80mpg and 70HP that tortures 4 fat assed adults.

The smaller cars with the smaller motors tend to give you a better base rate, still haven't given up on SUVs with v-8s here yet and switch to 1.2L motors in small cars.

The Ford Focus and a lot of vehicles like the Civic have smaller motors available with higher MPG, but they tend not to be offered in the US.
 
#2: wrong. The weight difference between (for example) an US-market BMW 5-series and EU-market 5-series is so small, it's irrelevant.

#3: close. Actually, the speeds that are taken into EU-standard mileage test are higher than those used in US, so the cars use a bit more fuel than they would in an US test.

#4: you mix up two things. A BMW 5-series ain't light, yet it averages better mileage than a Prius. And it's got over 100 HP more.


The correct answer is: different ECU mappings, which lean the mixture at the speeds and in the conditions that are used as reference for respective mileage tests in EU and US. This is the reason for different mileages in the "same" (yet EU/US) vehicles.

The other thing is, Europe has to pay much more for a gallon, so fuel-efficiency is a crucial issue here.
 
I'm just saying i will go to one company's US site, look at fuel economy for a car, then go to the UK site, and look at the same car. the UK will be way higher even after the US>UK gallon conversion. thats all
 
Because the petrol (gas) is a LOT more expensive here.

It is now around £5 a gallon. That's around $10.

http://www.whatcar.com/news-article.aspx?NA=231742

About 75 % of that is tax taken by the government.

I think it's still less than $2 for a gallon of Gas (petrol) in the US?

I think US gallons are slightly smaller but still a LOT cheaper.
 
Well US average is 3.26/gal and a UK gallon = 1.2 US gallons. I was just curious as to why UK cars get such better than US cars. I guess it's cuz the higher price. Just another thing i thought of was, how many miles a day do you typically have to drive, being in london? Europe has much shorter commutes than the US does, in general, you can drive across the entire UK in the distance of a few states here, so that can (im not sure) contribute to why our fuel is cheaper. Also, you have about 70% government tax if i'm correct.
 
I'm just saying i will go to one company's US site, look at fuel economy for a car, then go to the UK site, and look at the same car. the UK will be way higher even after the US>UK gallon conversion. thats all

The USA car sites get their MPG estimates from the EPA. Other countries' car sites get their MPG estimates from some other test cycle, such as the European test cycle which is less accurate to real world mileage than the EPA.

Of course the imperial vs USA gallon difference.

Engines tend to be smaller in Europe, a lot more diesels too due to less emissions requirements which increase cost and decrease MPG
Even with smaller engines, for instance the 71MPG rated VW Polo, it can only get 50MPG in real world driving
http://www.fuelly.com/car/volkswagen/polo/2012
 
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I remember seeing an M3 following a Prius being driven at max speed around a track on Top Gear. The M3 had much better fuel economy. It was a pretty irrelevant test IMO, and doesn't have much real-world value IMO. But I defiantly think it's more of 'how you drive' vs. 'what you drive'. I'm not saying a V8 truck will get better gas milage than a 4-cylinder car if driven right.

I get 30+ city MPG in my 12 year-old Acura, and I don't exactly drive like a grandma, yet people I know who drive similar cars can barely get 20 MPG. It's how they drive.
 
I skimmed through almost all the posts and no one answered the OP's question correctly. The biggest reason you see the difference is because of the regulations the US puts on emissions. Most vehicles in the US are required to have an EGR valve, which reduces pollution, but also GREATLY reduces gas mileage. There's also other valves/sensors that reduce pollution as well that can cause a variance in miles per gallon.
 
I remember seeing an M3 following a Prius being driven at max speed around a track on Top Gear. The M3 had much better fuel economy. It was a pretty irrelevant test IMO, and doesn't have much real-world value IMO. But I defiantly think it's more of 'how you drive' vs. 'what you drive'. I'm not saying a V8 truck will get better gas milage than a 4-cylinder car if driven right.

I get 30+ city MPG in my 12 year-old Acura, and I don't exactly drive like a grandma, yet people I know who drive similar cars can barely get 20 MPG. It's how they drive.

One of the news papers did a real world test here a few years back: drive from London to Geneva. They used a Prius and a BMW 5 series diesel. The 5 series used less fuel than the Prius. The Prius is great for feeling smug but pretty crap for actually returning good real-world fuel savings.
 
Well it is difficult to get less than 45MPG (US gal) with a 3rd gen Prius and definitely takes the lead in the city. On the highway they are neck and neck. With hypermiling, both can get stellar numbers.
If only VW made a smaller version of the diesel for the US, they'd be an even better choice. Right now I think their smallest diesel is 2 liters for the USA and 1.2 liters in other countries (Europe?).
Chevy I believe is releasing a diesel version of it's Cruze to the USA for 2013. 2Liter engine I think.
When HCCI gas engines come out it'll be interesting too.
Here are the fuelly numbers in USA MPG for the 2012 Prius
http://www.fuelly.com/car/toyota/prius

I'm glad the US has efficient choices these days, the cars are out there and it's up to the consumer to sacrifice some power for some fuel sippage, and in some cases no sacrifice in power. Smaller engine but the electric motor makes up for it, as long as you don't need that power for a long time.

I got a link the other day about this guy who took a trip to Europe and was amazed at the fuel efficiency. He said he was in a wagon that got 53MPG on a 2,000 miles trip (Imperial I believe) and how they had cars over there that got 70+MPG. What he didn't realize is that these 70MPG claims are from the European test cycle and tend to be a tad overestimated, and 70/1.2 translates to 53MPG in US gallons.
The wagon, 53/1.2 is 43.5MPG USA.
He is complaining about not having these cars in the USA but the Prius V is out and has basically the same cargo space as a Subaru Outback wagon but gets 40MPG+.
http://video.staged.com/localshops/vw_passat_785_mpg_in_the_uk

I looked up the VW Europe site and the most efficient car (Polo bluemotion) they had was 80.7MPG on the combined Europe cycle, which is 67MPG US gal.
http://www.volkswagen.co.uk/#/new/polo-v/which-model/engines/fuel-consumption/

I am seeing that people tend to get 60MPG US gal (maybe more?) if they drive sensibly on the highway. So the bottom line is that a small diesel is more economical than a 1.8 liter Atkinson cycle gas engine in a 3,000 pound versus 2,400 pound car (Prius vs Polo).

I would love (and I'm sure others would) a 1.2L diesel car, as a mild hybrid of course or a plug-in (for guilt free city driving and extra getup and go).

I'm scared that some people think that the engines in cars in the USA are somehow less advanced and refined that engines in Europe and that is why their mileage is so much better. But rather it is due to small diesel engines, Imperial vs US gallons, the European test cycle and emissions controls.
Would a lot of people in the US buy low powered diesel cars? I'm not sure, and that's what the automakers are thinking too. But make it a hybrid with a good sized electric motor and then the only compromise is manufacturing cost.
 
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I'm scared that some people think that the engines in cars in the USA are somehow less advanced and refined that engines in Europe and that is why their mileage is so much better. But rather it is due to small diesel engines, Imperial vs US gallons, the European test cycle and emissions controls.
Would a lot of people in the US buy low powered diesel cars? I'm not sure, and that's what the automakers are thinking too. But make it a hybrid with a good sized electric motor and then the only compromise is manufacturing cost.

I think that's a very good point.

Why are small diesels not liked in the US? I personally wouldn't buy anything else as I simply can't afford to run a petrol car anymore. (The idea of only getting a real world 28-30mpg makes my wallet squeak with fear!).

In the last 3 months two close friends have both recently sold their petrol cars (an Astra and a Nissan Note) and both have bought diesels as they couldn't afford to run them anymore with the MPG they were both getting.
 
Two main reasons are the price of petrol here in Europe is on average €1.65 per litre. Which is about $10.00 a gallon.

MPG/KpL are very important selling points, in the real world, of every day people.
 
Gasoline has traditionally been much cheaper in the United States than in most developed nations so American manufacturers just haven't had to worry about it as much.

Plus people here seem to have a thing for bigger or more powerful cars. I don't get the fascination but apparently it's nationwide.
 
Why are small diesels not liked in the US?

In the late 70's and early 80's there were some cars that used small diesel engines that performed horribly and died well before their time. It turned the buying public off of diesels for cars.

Diesels are still available for trucks, but most people don't get them unless they really need the towing capacity. It's not too easy to find a diesel in an American truck smaller than a 3/4 ton.
 
One of the news papers did a real world test here a few years back: drive from London to Geneva. They used a Prius and a BMW 5 series diesel. The 5 series used less fuel than the Prius. The Prius is great for feeling smug but pretty crap for actually returning good real-world fuel savings.

I thought the Prius was good for city driving, not highway driving.
 
I thought the Prius was good for city driving, not highway driving.

You're exactly right. The comparisons that Top Gear did proved one thing and one thing only: different cars have different strengths. A Prius isn't supposed to be a road trip car or driven hard around a track. One should expect it to do worse than cars that are more suited to that purpose. However, put that same Prius and M3 in L.A. traffic during rush hour on a Friday and the Prius will likely murder the M3. You wouldn't use a hammer on a screw, and yet pushing a Prius around a track flat-out is exactly that...
 
Well they are smaller and therefore lighter...

the people too

yes, alot smaller and smaller engines

I was shocked at how small cars were when I was in Austria and Germany. shocked

I didn't see a pickup truck at all I don't think. Here, it seems like a good 30-50% of cars here are trucks

Though their gas is like 7 bucks a gallon. Eff that. Probably cheaper to drive a truck here than a small car there lol
 
Funny how you guys talk about cost of fuel. I could care less. There is something wrong with our cars. Another ago top gear had a program where they were driving 600 miles on one tank of gas. They had a jag, Volkswagen, and I believe a Suzuki. Each one of them was getting way over 50 mpg and they showed the computer showing 64 mpg. The main character was trying to do everything possible to get less, but he stilly aged over 35 mpg. With a jag!!' So tell me why are we still struggling with our cars. A Prius struggles to get 45. I think our govt and fuel companies are good winking us!! I would neloeve that Better gas mileage will be less emissions since you burn less fuel???
 
We also jack up our gasoline here with ethanol which has a lower specific energy by volume.
 
We also jack up our gasoline here with ethanol which has a lower specific energy by volume.

Not only the 10% Ethanol year round in the USA but also winter gas has even less energy since winter gas is cheaper, has fillers like butane.

Top gear, when they are talking about MPG it's typically imperial gallons so you have to translate it down by dividing the imperial MPG by 1.2.
 
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