Topic: Fuel Economy: Gasoline vehicles getting as good as diesel?

[Curmudgeon]

Hi all - First post here.

I am researching for a new car. I'm currently driving a 2002 Focus ZX5. All in all I've been pretty happy with it, but I also know it has '2002' fuel economy. If I really stretch it I can get about 550km on a tank (mix of city and highway).

I've been looking at the VW TDI cars for awhile, and thought I may very well end up getting one for the extra mileage. I'm noticing, however, that several other 'regular' gasoline vehicles have pretty decent ratings, ALMOST getting into TDI territory. The ones I'm looking at so far are the 2012 Focus, Cruze, Fiesta and Mazda 2. I'm sure this is an apples and oranges comparison between the platforms, but based solely on economy (understanding I'm looking at posted numbers, and probably not real-world) the gasoline cars rate pretty good against the TDI models, and are less expensive.

Can anyone inform a non-car guy as to the benefits and drawbacks of both? I heard that a diesel engine will last longer, and I typically keep my cars for a long time. But whenever I look at the price of the TDIs I can't get over the extra thousands of dollars.

Thanks in advance.

[Ex-airbalancer]

I heard that a diesel engine will last longer, and I typically keep my cars for a long time

what is a long time?
what kind of mileage do you put on?
City or hwy driving?

[vdk]

My GF's friend has a 2006 Jetta TDI. She claims she drove Toronto-Montreal-Toronto on one tank.

Not sure you can do that with a gas engine.

[mmret]

The jetta and golf are rather heavier and more substanntial than the fiesta etc.

That's another way of saying that a Polo TDI would obliterate a gasoline powered subcompact.

[tpl]

VW used to advertise those pre-2007 TDI cars to get about 1000 km/tank

The current VW Polo gets between 60 and 80  mpg imperial  on the euro combined urban/suburban/ex-urban cycle depending on engine. (1.2 gas, 1.4 TDI )   Comes with 6 speed transmission or 7 speed dsg.


A few years back Top Gear drove a diesel  one around the M25 in the UK and got 75mpg.  The M25 trip would be like doing dvp->401->427->Gardiner-> dvp  in rush hour in either direction.

[Curmudgeon]

Answers to a few questions ...

what is a long time?
6-10 years

what kind of mileage do you put on?
Approx: 30-40k yr.

City or hwy driving?
Mix - But probably a bit more highway

I've been told that the 2012 Focus will get about 850km on a tank. I know it's not here, and there's a lot of 'ifs'. The base price of the 2012 Focus is $16k. The base price of the Golf TDI is $25k.

[Ex-airbalancer]

km per tank means nothing to me
Our Prius only takes 31 l most of the time I go  over 700 km

[vdk]

Answers to a few questions ...

what is a long time?
6-10 years

what kind of mileage do you put on?
Approx: 30-40k yr.

City or hwy driving?
Mix - But probably a bit more highway

I've been told that the 2012 Focus will get about 850km on a tank. I know it's not here, and there's a lot of 'ifs'. The base price of the 2012 Focus is $16k. The base price of the Golf TDI is $25k.

That qualifies you for a diesel.

[quadzilla]

My GF's friend has a 2006 Jetta TDI. She claims she drove Toronto-Montreal-Toronto on one tank.

Not sure you can do that with a gas engine.

There were a couple of cars/mini-vans advertised then said they could do over 1000kms/tank. Of course, they put a huge gas tank in them to achieve those numbers.

[No H2O]

I'm noticing, however, that several other 'regular' gasoline vehicles have pretty decent ratings, ALMOST getting into TDI territory.

Sure enough.

My 1983 boxy (read unaerodynamic) Toyota Corolla 1600 with a carburettor consistently got 51 to 53 MPGs on the highway at 105 km/hr. Not as good as a TDI of the time, but within about 15 MPGs.

I like the low cruising RPM and low end torque of a diesel.

[Blue01]

The distance a car can travel on a tank is really quite irrelevant. How big is the tank? 
You should be looking at lt/100km, or mpg.
That being said, if you want to compare a gas powered car with a diesel, add up all the costs incurred in the purchase, add in the estimated operating costs, what's the resale like, and look at how long you want to keep it.
In the end, which one will cost you less?
And, taking into consideration the other post showing CR's car reliability, give that a close look.

[vdk]

Most compact cars have a 55L tank.

[spicaphone]

I have a 2009 Yaris auto and regularly get 600+ km mixed driving about 46 mpg.The difference being 10,000 dollars between a fully eq. Yaris and the Volks.However you can't compare the comfort of the Volks compact to the sub-compact Yaris.For me since I do 36,000k a year on mostly rural roads and have limited funds the Yaris was the way to go.If you are going to keep it long term and do a lot of highway you will want the TDI.

[johngenx]

Fuel economy is one advantage of the diesel engine, but gasoline engines are getting better.  Our Corolla has amazing fuel economy for a car of its size.

The reason diesel engines generally last a long time is not because of the fuel, but because they have to built strong to withstand the high compression ratio.

One thing about diesels that I like is the amazing torque.  Our E300td Mercedes was wonderful to drive thanks to the low end grunt.

[rrocket]

Fuel economy is one advantage of the diesel engine, but gasoline engines are getting better.  Our Corolla has amazing fuel economy for a car of its size.

The reason diesel engines generally last a long time is not because of the fuel, but because they have to built strong to withstand the high compression ratio.

One thing about diesels that I like is the amazing torque.  Our E300td Mercedes was wonderful to drive thanks to the low end grunt.

On the flip side, I dislike the super low redline of many diesels....

[G35X]

If you are looking for a small high-efficiency car, how about the Mazda2 (and possibly Mazda3) with the new Sky-G gas engine, which will be available next year?  With its unusually high 14:1 empression ratio this engine is said to be very efficient (3.33 litres/100km in the case with the Mazda2).  High compression ratio means longer piston stroke (and, therefore, longer crank arm, cf. Subaru's new long-stroke H-4) making the engine more torqueful at low rpms. Interestingly Mazda’s other new engine, the Sky-D, comes with unusually low compression ratio of 14:1 for a diesel. Low compression ratio (for a diesel) means the engine’s NOX emission is low making it easier to meet the tough diesel emission regulations in Europe and elsewhere. More infor at:
http://www.caranddriver.com/news/car/10q3/mazda_sky-g_and_sky-d_engines-car_news

[tpl]

Fuel economy is one advantage of the diesel engine, but gasoline engines are getting better.  Our Corolla has amazing fuel economy for a car of its size.

The reason diesel engines generally last a long time is not because of the fuel, but because they have to built strong to withstand the high compression ratio.

One thing about diesels that I like is the amazing torque.  Our E300td Mercedes was wonderful to drive thanks to the low end grunt.

On the flip side, I dislike the super low redline of many diesels....

To be fair to the diesel. If it is paired with a modern 6 ( or more) speed  DSG or slushbox transmission it doesn't really matter much.  It will just be an endless supply of go just like a properly configured cvt.

[No H2O]

On the flip side, I dislike the super low redline of many diesels....

Whereas I dislike engines in daily drivers with where you have to rev the thing like a sewing machine to get anything out of them...the S2000 for example and there are many others.

On motorcycles we would say he has got to dance on the shifter all day long...referring to the typical in-line four Japanese motorcycle engine, especially the sub-1000 cc engines.