PDA

View Full Version : Petrol efficiency



paul_oshea
11/01/2008, 12:07 PM
what would one think a 1.4ltr engine should get on a gallon ( our one not the yankie one?! ) or say 15 litres? How much mileage would you expect to get out of it?

noby
11/01/2008, 12:13 PM
What kind of mileage? City driving would give you less mpg.

KevB76
11/01/2008, 12:20 PM
I had a 1.4 a few years back, used to get about 100 miles on a tenner, petrol was about 63p/litre back then :eek:

£10/0.63p = 15.9 litres / 4.54 = 3.5 gallons
100miles / 3.5 gals = 28.6 mpg

mixed driving (town / countryside / motorway)

anto1208
11/01/2008, 1:06 PM
my 2 litre coupe had 25.2 mpg on the computor this morning driving into work ( city driving ). So i guess about 30 on average driving for 1.4 L

pete
11/01/2008, 1:06 PM
As with all questions it depends. City or motorway driving?

paul_oshea
11/01/2008, 1:30 PM
mixed, im asking for both really, but in terms of motorway driving what would you expect?! i thought it was just under 5 litres a gallon?! not sure what kevin is saying above?!

The reason I ask is because I drove the parents car at christmas ( 1.3ltr 98 mazda 323, most efficient car ive ever driven ) and went to galway and back about 130 miles in total topped up about euro25 and still had a lot of petrol left for the rest of the week.

Driving a 1.4l over here motorway driving topped up £15 ( about 15 litres ) yesterday and after 100 miles its almost all gone, i cant understand it.

anto1208
11/01/2008, 2:32 PM
mixed, im asking for both really, but in terms of motorway driving what would you expect?! i thought it was just under 5 litres a gallon?! not sure what kevin is saying above?!

The reason I ask is because I drove the parents car at christmas ( 1.3ltr 98 mazda 323, most efficient car ive ever driven ) and went to galway and back about 130 miles in total topped up about euro25 and still had a lot of petrol left for the rest of the week.

Driving a 1.4l over here motorway driving topped up £15 ( about 15 litres ) yesterday and after 100 miles its almost all gone, i cant understand it.

Gallon is about 4 1/2 litres .

Lots of factors to consider Jap cars are better (what do you drive in the uk )smaller engine,Car weight. Motor way driving can still be quite heavy as people keep the revs up rather than using 5th gear. Petrol is much cheaper here 25 euro prob got you 22 litres here.you might have something wrong with the car that it idles higher or just burns more petrol.

OneRedArmy
11/01/2008, 2:46 PM
Generally, on motorway driving about 55 or 60 is the optimum fuel efficient cruise speed. Much above that and it drops, particularly in a smaller engined car.

I get 39mpg in a 2 litre diesel (BMW) on fairly mixed routes but outside of the cities my worst efficiency is when I'm sitting on the 120kph speed limit on the motorway on cruise control.

monutdfc
11/01/2008, 2:56 PM
Fuel efficient driving tips here:
http://www.eta.co.uk/pages/going-green-during-the-journey/ggduring/default.htm

"Keep your speed down as driving at 50-60 mph means your emissions will be lowest. Driving over 70mph will rapidly increase your emissions. It can cost you up to 25% more in fuel to drive at 70mph compared to 50mph."

Sligo Hornet
11/01/2008, 3:51 PM
mixed, im asking for both really, but in terms of motorway driving what would you expect?! i thought it was just under 5 litres a gallon?! not sure what kevin is saying above?!

The reason I ask is because I drove the parents car at christmas ( 1.3ltr 98 mazda 323, most efficient car ive ever driven ) and went to galway and back about 130 miles in total topped up about euro25 and still had a lot of petrol left for the rest of the week.

Driving a 1.4l over here motorway driving topped up £15 ( about 15 litres ) yesterday and after 100 miles its almost all gone, i cant understand it.


Did you remember to release the hand brake paul?;)

paul_oshea
11/01/2008, 3:58 PM
ah that was prolly it!!!

KevB76
11/01/2008, 4:22 PM
used to get about 100 miles on a tenner, petrol was about 63p/litre

£10/0.63p = 15.9 litres : amount of petrol for a tenner (£10 divided by price per litre)
15.9 litres / 4.54 = 3.5 gallons : convert litres to gallons (4.54 litres per gallon)
100miles / 3.5 gals = 28.6 mpg : calculate mpg - distance covered divided by amount of fuel used



mixed, im asking for both really, but in terms of motorway driving what would you expect?! i thought it was just under 5 litres a gallon?! not sure what kevin is saying above?!


Mine was actually quite poor mpg for a small 1.4 car, but I was lead-footed back then and was a "hot hatch" so efficiency wasnt one of its selling points.
By comparison my mothers 1.2 Punto returns about 52 mpg, mixed conditions, but you can squeeze about 65mpg out of it if you work at your driving style, but it'll end up costing you on repairs cos those feckin trip computers are a distraction!!!

As others have pointed out, there are many many variables to consider. To cut to the chase if your'e not getting at least 40mpg on average from a modern 1.4 then there's something wrong with the car or with your driving style :p

KevB76
11/01/2008, 4:40 PM
Motor way driving can still be quite heavy as people keep the revs up rather than using 5th gear.

That is so stupid, they might as well be lobbing fivers out the window with the amount of extra petrol they'll burn, the car will go just as fast in 5th but use less petrol and with less wear on the engine :rolleyes:


you might have something wrong with the car that it idles higher or just burns more petrol.

Idle speed has feck all to do with your mpg unless you spend most of your time stuck at traffic lights!!
More likely factors would include under-inflated tyres, or dirty air filter, coked up spark plugs etc..

ramsfan
11/01/2008, 5:13 PM
drive a 1.4 astra, mixed driving town and long stretches getting around 38 -43 mpg:D

gaiscíoch
13/01/2008, 9:14 PM
My 1.9litre tdi A4 will produce 56mpg regardless of how I drive it or what gear etc,
Tips for saving fuel:
Keep your windows up (down causes drag, on the engine requiring higher revs to maintain speed)
Keep your stereo volume down (the higher the volume the more energy required from the engine to power the battery)
Keep the revs down (obvious enough (block changing through down gears is advisible)
Make sure your tyres are fully inflated 32psi (again just causes drag resulting in higher revs due to friction)
Keep the fans off
Some of you may already know these but for those who dont i hope this helps.
Regards
Your friendly nieghbourhood engineer.

pete
14/01/2008, 11:26 AM
On my 1.8L petrol I would expect 35mpg + on Dublin-Cork route. Would not like to calculate the mpg on City Centre driving as would probably shock me.

pineapple stu
14/01/2008, 5:34 PM
My 1.9litre tdi A4 will produce 56mpg regardless of how I drive it or what gear etc,
Highly unlikely (both the consumption for a 1.9l and the consistency). This article (http://uk.cars.yahoo.com/car-reviews/car-and-driving/audi-a4-1.9-tdi-115-1004069.html) notes a range of between 37.2 and 61.4mpg, and even then that's the car manufacturers trying to make it sound good.

Gaillimh Al
14/01/2008, 5:48 PM
My '98 1.4 does between 35-50mpg depending on where I am travelling. Think thats good for an older car, especially with quite a bit of city driving.