Shocked at petrol consumption after years of driving diesel's

dnme

Tipping around Galway County in my 98 Corolla 1.3L. It's the first petrol car I have owned in years. Up to now I have been driving diesels with my latest being the Megane 1.5DCi. That used to give me 65+ mpg. I used to fill it up and it would take forever for the needle to move at all.

Sweet jesus, this petrol malarchy is a different ball game altogether. You go for a spin for a few miles and you can see the needle has moved especially if I go over 50 mph. I'm just amazed, I thought modern engines with ECU's etc would be so much better especially in 1.3. And its a far more expensive fuel.

eniale

The OH is the exact same, always cribbing about the speed of the petrol gauge in my car after driving diesels for so long.
A '98 corolla isn't cutting edge technology though! I've a 98 318is and am getting 39/40 mpg - not bad for a 1.9 petrol, but a lot of that is down to a good engine management setup:)

Leonard Hofstadter

Little engines like a 1.3 are put into cars that size as an afterthought specially for cost consciousstupid Irish people who will not buy an anyway decent sized engine, it is not in the slightest bit surprising that a low power engine does not produce good fuel economy, I've been saying this to people for years but I might as well be banging my head off a wall, "sure look at all the tax I'm saving":rolleyes:.

Alanstrainor

captainspeed wrote: »

Little engines like a 1.3 are put into cars that size as an afterthought specially for cost consciousstupid Irish people who will not buy an anyway decent sized engine, it is not in the slightest bit surprising that a low power engine does not produce good fuel economy, I've been saying this to people for years but I might as well be banging my head off a wall, "sure look at all the tax I'm saving":rolleyes:.

Haha, yeah. It's madness. I remeber driving an 03 1.4 focus for a couple of years, and you could literally see the fuel gauge just fly down all the time. No matter how i drove it, it drank petrol, i mean i wouldn't have minded if it was at least a nice engine with some poke, but it wasn't. Handled well i suppose.

SV

I can get over 55mpg driving very carefully in my 2litre petrol car.
It's all about how you drive it

JHMEG

gt112 wrote: »

my 98 Corolla 1.3L...... I thought modern engines with ECU's etc would be so much better especially in 1.3.

A 12 year old 1.3 Corolla has a far from modern engine. Is it even fuel injected?

albob

Just to say that I currently drive a 99 corolla 1.3, and get 45mpg. Granted 80% of my driving is a 50mph constant commute 2 hours a day, but still not too bad. Going for scrap now though.

Leonard Hofstadter

JHMEG wrote: »

A 12 year old 1.3 Corolla has a far from modern engine. Is it even fuel injected?

It's a 16 valve twin cam engine, all cars have had fuel injection since 93. Not state of the art but same technology that's found in a Fiesta or Focus petrol or a Megane petrol.

dnme

So guys, seeing as I am a conservative driver (light footed) and happy at 50-60mph, are you saying that I would getter better fuel economy in a 1.6 or 2L in the same sized body? Interesting.

I still think that a modern 1.3 should be able to manage the Corolla (tilt back is what I have). I genuinely am shocked at how this thing gulps petrol. I'm gonna brim it and do a precise measurement. Will report back in a week or two.

OldmanMondeo

captainspeed wrote: »

, all cars have had fuel injection since 93. .

Not my old 98 Megane 1.4 8v, big old carb under the bonnet, greatest peice of **** I ever had.

OP I notice the same with my 2.0 TDCi Mondeo and her 1.6 Qashqui, her petrol does half the distance per tank to mine, Qashqui is probably lighter and is within 5bhp of the Mondeo.

I would only buy a petrol car now if I was looking for performance, since I am getting near the top of the hill, ready to go down the other side, I will stick with a Diesel car.

Leonard Hofstadter

All euro spec Renaults have had some sort of fuel injection since 93, it effectively became compulsory because cats were made compulsory back in 93, and you can't have a cat without fuel injection.

The Quashqow as I like to call it is much less aerodynamic and has a too small for size of car 1.6 so it is no surprise that the Mondeo does double the mpg. Because the Mondeo has loads more power it doesn't need to be revved as much which is the real reason why in the real world a larger engine(up to a point, I mean a V6 Mondeo won't be giving better economy than a 2l but a 2l would definitely be better than a 1.6) gives better economy.

JHMEG

captainspeed wrote: »

It's a 16 valve twin cam engine

That dates back to 1989

captainspeed wrote: »

, all cars have had fuel injection since 93.

No they haven't. My old 1995 Civic 1.3 was carburetted.

captainspeed wrote: »

Not state of the art but same technology that's found in a Fiesta

No, the Fiesta 1.3 is a pushrod engine, dating back to the 1950s.

Berty

Thank yourselves lucky you do not have a FFV 1.8 as a workhorse.

It has drank a lot of fuel this week already and thats only from Ennis to Limerick - Galway - Limerick - Galway. Im in Galway now. I HAVE half a tank left and expect to be on the red line by the time I get back to Limerick. I still have to go around East Clare, North Tipp and Athlone before Friday is over so I expect at least 2 more tanks of fuel making 4 tanks of fuel over a 5 day week.

FUPPPPPSSSSS SAKE!!!!:mad:

1 tank of diesel would have covered all these journeys and being just under half the price of the fuel. The E85 pump was out of order last night so had to take unleaded instead pushing the price up evenmore. There are two petrol stations between Limerick Clare and Galway(area I cover). None in Galway, one in Ennis and one in Limerick.

Stupid employers! :mad:

Leonard Hofstadter

JHMEG wrote: »

No, the Fiesta 1.3 is a pushrod engine, dating back to the 1950s.

Sorry, I should have said that it's the same technology as what's found in a new Fiesta/Focus/Megane. The pushrod engine in the Feshty died years ago.

JHMEG

captainspeed wrote: »

The pushrod engine in the Feshty died years ago.

Was still in use in 1998

unkel

captainspeed wrote: »

All euro spec Renaults have had some sort of fuel injection since 93, it effectively became compulsory because cats were made compulsory back in 93, and you can't have a cat without fuel injection.

I'm pretty sure all cars sold in the Eurozone have a cat since 93. That's right. I remember the EU '93 emissions norms were similar to the ones that came into action in California in '79

So how come some cars still had carbs?

mickdw

SV wrote: »

I can get over 55mpg driving very carefully in my 2litre petrol car.
It's all about how you drive it

I call bull**** unless you are one of these hypermile people and if so, that is nothing short of dangerous.
What car is it?

unkel

JHMEG wrote: »

Was still in use in 1998

Much later than that if I remember right (Ford Ka). That said, from about the mid 90s, there was also the 1.25 16V Yamaha engine in the Fiesta. But the old 1.3 was probably cheaper to buy - so very poplular here

unkel

unkel wrote: »

Much later than that if I remember right (Ford Ka).

Yep, awful noisy little heavy engine.

JHMEG

unkel wrote: »

So how come some cars still had carbs?

Because they were clean enough to pass the emissions standards of the time, even in 1995. However in the mid-90s the US passed legislation making them illegal in new cars. GM etc were unable to meet emissions regs without using EFI, and put pressure on the govt to outlaw (cheaper) carbs. It made no sense to continue carbs in the rest of the world after that.

unkel wrote:

Much later than that if I remember right (Ford Ka).

I remember reading somewhere that Ford devised the Ka as a mechanism to sell the backlog of 1 million Enduro E engines they had left over from the Fiesta, and it proved to be very successful. Dunno if it's true or not.

dnme

Can we get over the pedantics as I was hoping for a constructive on topic debate here (sorry mods, not tryin to back seat moderate, feel free to kick/delete).

I think, if you consider the potential energy stored up in petrol, its massive!, when I see how petrol cars perform, we must be wasting so so sooooo much of that energy. I reckon we are at about 20-30% efficiency at best if that.

I think its bloody dissapointing that in 2010, a petrol engine struggles to get 40mph. We should have the technology in place to harnass the masses of energy in petrol, we should be gettin 80mpg +.

Surely the days of petrol slugging waste mobiles are numbered ?

Alas when it comes to diesel, we lost reliability to high pressure.

Stark

I get about the same fuel efficiency from 1.6L ford focus petrol saloon (04) as a friend gets from his citroen xsara 1.9L diesel. I imagine the 1.6L is probably more efficient than the 1.4L as the 1.4L saloons tend to be constantly labouring.

SV

mickdw wrote: »

I call bull**** unless you are one of these hypermile people and if so, that is nothing short of dangerous.
What car is it?

Renaultsport clio 172
http://img39.imageshack.us/i/009xpv.jpg/

unkel

JHMEG wrote: »

Because they were clean enough to pass the emissions standards of the time, even in 1995.

That makes sense. Most domestic cars in the US used much bigger much older engines in bigger heavier cars. Tiny euro or jap 4 pots were probably getting away with it until the next tighter emission rules.

JHMEG wrote: »

I remember reading somewhere that Ford devised the Ka as a mechanism to sell the backlog of 1 million Enduro E engines they had left over from the Fiesta, and it proved to be very successful. Dunno if it's true or not.

They'd hardly a million engines in stock, did they?

Anyway the old Kent based engine is much vilified here. Let's face it, a lot of Fiestas are used as shopping trolleys / first cars for people who know nothing about cars. The get the 1.3 cheaper, spend the same in tax and insurance and an unnoticably higher amount on petrol and never have to worry about cambelts compared to the 1.25. The former has 60BHP which is adequate in a supermini. Most of the competitors had less.

JHMEG

unkel wrote: »

That makes sense. Most domestic cars in the US used much bigger much older engines in bigger heavier cars. Tiny euro or jap 4 pots were probably getting away with it until the next tighter emission rules.

It wasn't really an issue of displacements as the foreign makes had V6s passing emissions fine on carbs. It was lazy design by the domestic makers as petrol was cheap.

unkel wrote: »

Let's face it, a lot of Fiestas are used as shopping trolleys / first cars for people who know nothing about cars.

Absolutely. My next door neighbour used to have one. It rattled more than a VAG diesel and she used 'dip' it for oil by taking off the oil cap and sticking a bit of 2 by 1 in.

unkel

SV wrote: »

Renaultsport clio 172
http://img39.imageshack.us/i/009xpv.jpg/

Times must be real bad that you are forcing yourself to try getting 55MPG from your Renaultsport

BlackWizard

unkel wrote: »

Times must be real bad that you are forcing yourself to try getting 55MPG from your Renaultsport

I think that makes it more fun! It would for me anyway. It's fun tweaking an old machine to try and get the best of her

mickdw

SV wrote: »

Renaultsport clio 172
http://img39.imageshack.us/i/009xpv.jpg/

I could also produce a pic showing any figure you like for consumption on my 1.8T audi. That proves nothing. If however you are averaging that figure and its not just taken over a few miles of cruising, well why own that car at all. Driven properly differently, Im sure 25 mpg would be more like it.

SV

mickdw wrote: »

I could also produce a pic showing any figure you like for consumption on my 1.8T audi. That proves nothing. If however you are averaging that figure and its not just taken over a few miles of cruising, well why own that car at all. Driven properly differently, Im sure 25 mpg would be more like it.

jesus christ, do you want a video to prove it or something? :rolleyes:

Oh I dunno, why on earth would I want a car that can achieve that kind of mpg but also quite fast when I want it to be.
who knows! :rolleyes:

SV

unkel wrote: »

Times must be real bad that you are forcing yourself to try getting 55MPG from your Renaultsport

I could take a pic of what it's been showing for the past few days if you want? It's not pretty

samsemtex

I get 40mpg on the motorway from my 1.8 Volvo S40 petrol. I think that is pretty impressive in a car of its size/weight.

itarumaa

It is a bit shocking to own 2l petrol and see figures about 29mpg, I have never seen 40mpg in that car:)

But the point was that it was cheap to buy and therefore cheap to own because you do not lose much money over the years,

still sometimes it feels a bit silly to drive alone to work and back when something like Smart would give same result but with way better fuel consumption.

peasant

on topic:

Diesel engines generally achieve greater fuel efficiency than petrol (gasoline) engines. Diesel engines have energy efficiency of 45% and petrol engines of 30%.[3] That is one of the reasons why diesels have better fuel efficiency than equivalent petrol cars. A common margin is 40% more miles per gallon for an efficient turbodiesel. For example, the current model Skoda Octavia, using Volkswagen engines, has a combined European fuel efficiency of 38.2 mpg for the 102 bhp (76 kW) petrol engine and 53.3 mpg for the 105 bhp (78 kW) — and heavier — diesel engine. The higher compression ratio is helpful in raising the energy efficiency, but diesel fuel also contains approximately 10-20% more energy per unit volume than gasoline which contributes to the reduced fuel consumption for a given power output.[4]

http://en.wikipedia.org/wiki/Fuel_efficiancy

dnme

peasant wrote: »

on topic:

http://en.wikipedia.org/wiki/Fuel_efficiancy

I knew there'd be one

Leonard Hofstadter

The gap between petrol and diesel is closing though, for the Octavia now the 1.2 TSI which basically is the replacement for the old 1.6 does 49.6 mpg while the 1.6 TDI which is the replacement for the 1.9 TDI does 62.8 mpg. Both have 105 bhp.

The diesel is 26% more economical, quite a gap and probably more in the real world seeing as you wouldn't have to rev the diesel as much, still a fairly significant gap but at the same time it is a lot better from the petrol point of view when you consider that the gap was over 40% at one stage.

dnme

captainspeed wrote: »

The gap between petrol and diesel is closing though, for the Octavia now the 1.2 TSI which basically is the replacement for the old 1.6 does 49.6 mpg while the 1.6 TDI which is the replacement for the 1.9 TDI does 62.8 mpg. Both have 105 bhp.

The diesel is 26% more economical, quite a gap and probably more in the real world seeing as you wouldn't have to rev the diesel as much, still a fairly significant gap but at the same time it is a lot better from the petrol point of view when you consider that the gap was over 40% at one stage.

sure I remember a year or two ago, diesel became more expensive than petrol at the pumps, which surprised everyone. But as a rule, yeah diesel is and should be cheaper as there is less refining to do. (which makes the fact that petrol is less efficient even more painful)

unkel

SV wrote: »

I could take a pic of what it's been showing for the past few days if you want? It's not pretty

Single digit not pretty?

R.O.R

I'm absolutley feckin delighted with the consumption on my last tank of petrol. 768km from 54.12 litres (brimmed each time, reading from trip). My workings for that come to 7.05 l/100km which apparently converts to 40.07 mpg.

I'd say it's because the N3 and N2 junctions on the M50 have been sorted so there is very little deviation in speed.

2005 Honda Accord 2.0i VTEC with about 137,000km is my trusty steed. Probably get about 1,200km from a full tank on a modern diesel.

GERMAN ROCKS

R.O.R wrote: »

I'm absolutley feckin delighted with the consumption on my last tank of petrol. 768km from 54.12 litres (brimmed each time, reading from trip). My workings for that come to 7.05 l/100km which apparently converts to 40.07 mpg.

I'd say it's because the N3 and N2 junctions on the M50 have been sorted so there is very little deviation in speed.

2005 Honda Accord 2.0i VTEC with about 137,000km is my trusty steed. Probably get about 1,200km from a full tank on a modern diesel.

i thought you had a new opel insignia sri

unkel

GERMAN ROCKS wrote: »

i thought you had a new opel insignia sri

He has a lot of cars - see his sig

R.O.R

GERMAN ROCKS wrote: »

i thought you had a new opel insignia sri

unkel wrote: »

He has a lot of cars - see his sig

I have one car, but drive a lot of different ones for work.

SV

unkel wrote: »

Single digit not pretty?

Just after a sprint from 0-146ish mph(indicated) on a 'private road'

when you start driving normally (but aggresively) it'll come to about 25ish which isn't all bad.

unkel

SV wrote: »

on a 'private road'

I usually do it on a road that is very smooth and so 'private' that you have to pay the owner to use it

VolvoMan

unkel wrote: »

Much later than that if I remember right (Ford Ka).

Indeed.

And it sounded like a skeleton **** in a biscuit tin!:D

VolvoMan

VolvoMan wrote: »

Indeed.

And it sounded like a skeleton **** in a biscuit tin!:D

lol, I must service one this weekend, if it doesn't rain.

rafo802

Yeah, am a big fan of diesels, it's is the only way to go.
Decent diesels would getting an average of 50mpg even the older models.
Some of the better figures quoted here for petrols are way off in my opinion, 40mpg for a petrol...doubt it. 35mpg at best.

air

gt112 wrote: »

I think its bloody dissapointing that in 2010, a petrol engine struggles to get 40mpg. We should have the technology in place to harnass the masses of energy in petrol, we should be gettin 80mpg +.

captainspeed wrote: »

The gap between petrol and diesel is closing though, for the Octavia now the 1.2 TSI which basically is the replacement for the old 1.6 does 49.6 mpg while the 1.6 TDI which is the replacement for the 1.9 TDI does 62.8 mpg. Both have 105 bhp.

The diesel is 26% more economical, quite a gap and probably more in the real world seeing as you wouldn't have to rev the diesel as much, still a fairly significant gap but at the same time it is a lot better from the petrol point of view when you consider that the gap was over 40% at one stage.

I would venture that there is actually very little between diesel and petrol engines in terms of efficiency.
Both contain similar amounts of energy per unit weight (approx 46MJ/kg) however we buy fuel by volume and diesel is between 12 and 30 percent denser than petrol (depends on the source and refinement I guess).

The upshot of this is that there is more potential energy in a litre of diesel than there is in a litre of petrol. As we typically measure engine efficiency in terms of distance travelled per litre, the diesel engine appears more efficient when in fact there is likely not as big a difference as one might think.

When you add to this the fact that we pay less for a litre of diesel (despite getting more Joules per Euro from diesel) then it moves things in diesel's favour even more (from an economic point of view).

On the other hand petrol engines do release more CO2 per unit of distance travelled (in general) and my argument does not help a petrol engine in this regard.

http://www.kayelaby.npl.co.uk/chemistry/3_11/3_11_4.html
http://www.simetric.co.uk/si_liquids.htm

Idbatterim

Op take a look at the below link!

http://www.youtube.com/watch?v=dKTOyiKLARk

testicle

SV wrote: »

I can get over 55mpg driving very carefully in my 2litre petrol car.
It's all about how you drive it

Granny? Is that you?

SV

testicle wrote: »

Granny? Is that you?

see post 42.

Del2005

air wrote: »

On the other hand petrol engines do release more CO2 per unit of distance travelled (in general) and my argument does not help a petrol engine in this regard.

Diesels produce much more pollution then petrols. But the governments have decided that CO2 is the only thing that kills people not soot particles, NOx etc which cause lots more issues then CO2