[Closed] Turbo petrols vs diesel

We chopped in our aged Ibiza FR Tdi for a Fiesta 1.6 Ecoboost ST3, much better car to drive and similar economy on the 5 mile each way commute, a hair less on a long run but close. Completely terrible economy when driving like pants are on fire, but so much fun, who cares?

I'm intrigued by Ford 2.5Ts now though.

It's the old Volvo T5 engine, which was 'quite good' even when mounted in two tons of scandinavian beige estate!

As noted above, it's more 'boost', considerably less 'eco'.

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Inbred456 speaks sense.

I'm in the process of changing from DERV to petrol, I do approx 18k miles per year, mostly on motorways, and recon that a petrol car will cost me about £20 a month more in fuel (based on Honest John's real mpg figures).

Having test driven the Golf, Focus, Leon, V40 and a Mazda 3 I decided to get a Mazda 3 2.0 petrol, no turbo, no intercooler.

The insurance and VED are £50 a year less each than my current car (2010 Skoda Superb, 2.0d DSG).

Pimpmaster Jazz - Member

I'm intrigued by Ford 2.5Ts now though.

The new 3.5 is where it's at. 450bhp 510 lb-ft.

Murica.

thisisnotaspoon - Member
It's the old Volvo T5 engine, which was 'quite good' even when mounted in two tons of scandinavian beige estate!

Actually your about 1/2 Tonne out it was only 1500kg ish with the present Golf Estate only just over 100kg lighter!!

The main thing with turbo petrol engines is that they can easily match horsepower, but they lack torques, and often they have only had a 5-speed box, so while a diesel might be tootling along at around 2000rpm in top, a petrol is likely to be around 3000rpm, now that 6-speed boxes are starting to become more common, cruising rpm is dropping and economy improving. I've lost track of the number of petrol cars I've driven, and I'm doing 75-80* in top on a motorway, and looked at the tacho and though "why the **** hasn't this got another gear! It's running at least 1000rpm higher than a diesel!"
*Indicated, 73-76 GPS. 😛

I've just gone from turbo diesel golf estate - nice bit of motorway grunt - to a Mini Cooper S 😆

Bristol is about to start making it much harder for diesels to get about (quite rightly so) so I thought I'd get something less dirty.

Both will depreciate rapidly in next five years. Motoring is emerging from the dinosaur age.

Caveat emptor (with old technology)

Petrol. No DPF and less likely to have a dual mass flywheel. Win-win

Don't need to have the cam belt changed until 100,000 miles unlike VAG cars which a 13/14 plate will probably need doing.

so while a diesel might be tootling along at around 2000rpm in top, a petrol is likely to be around 3000rpm, now that 6-speed boxes are starting to become more common, cruising rpm is dropping and economy improving. I've lost track of the number of petrol cars I've driven, and I'm doing 75-80* in top on a motorway, and looked at the tacho and though "why the **** hasn't this got another gear! It's running at least 1000rpm higher than a diesel!"

I'm intrigued by Ford 2.5Ts now though.

They used to be fitted to the Focus ST range also. 5 cylinders and 2.5 litres of turbo charged loveliness!

Back to the OP's question - I'd recommend looking at a Leon 1.4 EcoTSI with the 7sp DSG in FR Spec.

I'm intrigued by Ford 2.5Ts now though.
They used to be fitted to the Focus ST range also. 5 cylinders and 2.5 litres of turbo charged loveliness!

I think also in the Volvo V40 R design, which is Focus based.

I was driving a Ford petrol in Canada recently. 6.8 litre V10. Not especially eco...

The main thing with turbo petrol engines is that they can easily match horsepower, but they lack torque

The modern 1l turbo petrol engines have a surprising amount of torque. My daughters 1L 125bhp fiesta feels like it has a much bigger engine, especially at lower revs.

I test drove a Dacia Lodgy TCE 115 (same engine as the Renault Megane) and turbo diesel 110. I never seriously considered the diesel for public health reasons but was intrigued by how they drove back to back. The petrol pulls strongly from 2000rpm and goes better from then to when you deem it time to change up. The petrol is smoother, quieter and will pull smoothly from very low revs if you are easy on the gas.

Both petrol and diesel are gutless at low revs, noisy, smelly, filthy, unrefined and have irritating transmissions. Test drive an electric car and see for yourself.

Test drive an electric car and see for yourself.

Sadly not practical for my circumstances yet.

Welll the diesel estate goes in next week to be replaced by a petrol turbo. It's a 9speed auto and so will probably be a shade less economical than the 7speed diesel it's replacing. The new one has plenty of torque over lots more revs than the diesel so with the 9spds it's goes well.

That will probably be my last diesel after 25yrs of driving them. I suspect that it will be hybrids or pure battery powered from now on

After much scepticism I've had a skoda superb 1.4tsi for a few years now. Smooth and pulls well, never struggles even loaded. Think it averages about 35 mpg with 50.50 town and country driving.

What do you need torque on a 5 mile commute for? A turbo petrol engines car will produce ample torque for that. My wife's 1 series petrol 1.6turbo is a great car for local run around and commuting duties and even long motorway trips and not lacking in torque or power in any way. Far better than a diesel for those duties. And with the 8 speed auto box chugs along at motorway speeds in the low 1000's of rpm. Economy is around the high 30's low 40's but I can't say we're in any way driving him the most economical way possible. Like any car, even diesels, he mpg you achieve has more to do with how you drive the car.

So for my two penneth worth get a petrol turbo. Quieter, smoother, more refined, nicer torque delivery and more useable spread of power across the rev range than a diesel. Also less complicated and cleaner. Also won't chew through front tyres (assuming fwd), and cheaper to buy and run for a good 40 k miles or so at least, or wherever trade off is these days between cheaper up front costs vs. Fuel economy.

I'll be getting shot of my 2.0 Tdi Yeti 4x4 in October. It's been fine up until the emission fix was done this summer. I managed to put it off for over a year nearly until its annual service. Notably more re-gens and a lack of torque at low rpm. I'm thinking of buying second hand again. Mazda 6 2.5 Sport petrol estate is on the horizon. Old school but lovely to drive and fairly reliable. 10k a year so fuel costs shouldn't be to high. The Yeti averages about 41 mpg.

I'm a company car driver and on his occasion I went diesel. Imagine it'll be my last one though - fully expect to be getting a hybrid petrol or an ev next time (about 3.5 years away).

I do enough long trips frequently enough and the company car tax currently on pure petrol was bad enough to justify the diesel for now. Couldn't get a decent hybrid on my budget.

My wife does similar trips / mileage to the op with a commute through stop-start traffic so she has a petrol car and when she changes will be getting another petrol car I expect. Currently in a not very economical Mini Countryman Cooper s - think we'll be looking at one of these smaller engines turbo petrols to replace it.

For me (and now the wife) an automatic gearbox is high on the list. My car has the 8 speed zf box with paddles and it's a game changer for me. Used to love a manual but on long trips and in stop start traffic I love the auto. Generally leave it in Drive or sport but play with the paddles occasionally.

Just to add last year I had a Citroen ds4 as a hire car and it had a 1.2 turbo petrol engine with about 140bhp. It was really good actually. Quiet but carried a surprisingly big stick when you put your foot down.

wobbliscott - Member

What do you need torque on a 5 mile commute for? A turbo petrol engines car will produce ample torque for that.

He's asking about a small displacement petrol engine in a bigger car. Conventional logic is that you need a big diesel to have a pleasant driving experience.

We have a 1.0l ecoboost 125hp in our cmax (2014)

We've had it a year, no reliability issues at all.

It is surprisingly nippy, even in a big-ish car. On a test drive that'll almost certainly be your impression.

However I find it occasionally annoying. It is still underpowered as you would expect for a 1.0, but only in certain situations, like pulling away quickly or overtaking.

Feels like there's a very narrow margin between too much torque, and nearly stalling the engine. Even after a year I can't get used to it.

Mpg is pretty poor around town. Even driving really carefully and frugally I can't get more than high 30s. 'Normal' driving with the A/C on its around 35. On the motorway I reckon I'd get 50mpg or so if I stuck to 65mph.

Overall I'm still happy with the car but the engine is the weakness, if these things bother you. Hopefully it'll continue to be reliable.

He's asking about a small displacement petrol engine in a bigger car. Conventional logic is that you need a big diesel to have a pleasant driving experience.

Yes, but depends on how fast you want to accelerate. Big diesels give you torque low down which means people generally use it and get used to it, but it's not needed. Anyway it's a question of hearing. Small turbo petrol engines will be low gear d to give you poky acceleration. My mates 1.0 Ltr ecoboost b-max (so not a small car) feels pretty poky on acceleration even with two burly bikers, a couple of burly bikes and a weekends worth of bike gear stuffed in it.

I have no particular loyalty to petrol, diesel, electric or even chip fat or Lpg. I've used it all, except electric, and that'll likely change soon. But in my mind it's the bizarre pricing of fuel that's the issue. You've got petrol and diesel being priced and therefore compared by volume, despite diesel being 15% more energy dense by volume. You've got electric being viewed as the efficient saviour of humanity, yet if it were priced (taxed) comparably to other fuels it would be just be a less convenient, massively less energy dense white elephant. The biofuel boom a few years ago only succeeded in putting some food crop prices up as there's a finite capacity to grow oily crops.

Noes the time to go electric, if you can. As soon as the government coffers start to take the hit from widespread uptake of electric transport, they'll have no choice but to tax it similarly. S'maths, innit?

Much of the electricity will be free, collected on peoples roofs from the orange ball in the sky.

Its more likely the tax will come from miles travelled which seems fair.

wobbliscott - Member

He's asking about a small displacement petrol engine in a bigger car. Conventional logic is that you need a big diesel to have a pleasant driving experience.

Yes, but depends on how fast you want to accelerate. Big diesels give you torque low down which means people generally use it and get used to it, but it's not needed. Anyway it's a question of hearing.

It's not necessarily about how fast you want to accelerate (and that's very subjective anyway), it's about in gear acceleration and usable power curves that compliment the size, weight and intended purpose of the car.

Small turbo petrol engines will be low gear d to give you poky acceleration. My mates 1.0 Ltr ecoboost b-max (so not a small car) feels pretty poky on acceleration even with two burly bikers, a couple of burly bikes and a weekends worth of bike gear stuffed in it.

It's not the gearing it's the power delivery. Your mate's 1.0 ecoboost has a tiny turbo that spins up from very low revs and delivers 90% of peak torque below 2000 rpm much like a diesel.

You've got electric being viewed as the efficient saviour of humanity, yet if it were priced (taxed) comparably to other fuels it would be just be a less convenient, massively less energy dense white elephant.

How many times a year would you have to do anything more than plug in your car on arriving home?

[url= https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/514912/road-use-statistics.pdf ]The average trip length is just 7 miles.[/url]

Infrastructure is in its infancy but we crossed France to Germany with enough charge points.

If the current system were electric based and someone suggested having tankers full of explosive liquids delivering petrol stations with huge tanks of explosive liquids and then having 60l of explosive liquid in every car how would people react?

how would people react?

Explosively? 😉

How many times a year would you have to do anything more than plug in your car on arriving home?

There's no incentive to drive a far more expensive and less versatile vehicle such as two-seater Mini. Or a Tesla (which is a lot more practical), they do though. Not everyone wants to drive a Dacia Lodgy TCE (if you can think of a more cost efficient and versatile car insert that here), they buy different vehicles for different reasons and the cost per km is way down their list and the tax they pay even lower. It's mainly about image and percieved quality of experience as people's comments on the relative merits of petrol and diesel engines on this thread demonstrate.

I like the invisible silent hand pushing me forward (and holding me back with energy recovery when I brake) sensation from an electric motor and that's as much a part of the deal as zero local emissions or the cost per km.

I like the invisible silent hand pushing me forward (and holding me back with energy recovery when I brake) sensation from an electric motor

This makes NOW the best time to own an electric car, before everyone has got one and they can start ratcheting up the tax.

I've just checked my electricity bill, I'm paying top rate VAT and some local taxes too.

The Government (UK, French, etc) cannot afford to lose the tax revenues from motoring fuels, so if we all switch to electric they will have to charge us somehow. Back of the envelope we pay £1000 pa on fuel tax/duty - so that will be the road tax charge or some other mechanism of taxation. (Wiki says UK motorists pay £38bn pa in road tax and fuel duty/vat - that number sill need to keep rising to pay for Government spending)

Some kind of hike in electricity prices then? Perhaps it's time to invest in a Tesla solar roof and powerwalls before "the man" starts getting his.

12.1 kWh/100 km x 7500 km = 907kWh per year, say 1000kWh + if you include charging inefficiencies. Add to that house consumption of 1600kWh and we still consume less than the 3400kWh our solar panel produce.

What I hope will happen is the same as with cigarettes. As EVs take over the tax on fossil fuels will steadily be increased as it has been with cigarettes so smokers pay progressivley more tax for their anti-social habit.

Reciepts from vehicle licencing have been falling for a while hence the change this year.

From memory its about 5 billion with the remainder 30+ coming from fuel duty.

The loss of that 30 billion will be gradual over the next 50 years.

There are going to be big changes as we see an increase in not only electric cars but also self driving cars and a I suspect a lot more people using car share type schemes.

Less fuel duty and most likely revenue from speeding fines. Potentially much less accidents and much lower pollution related illness so maybe some savings for the government to offset the taxes.

I've not seen any figures yet but surely running costs for electrics cars should be much lower and when things steady out with 2nd and 3rd gen vehicles I can see depreciation slowing greatly so coupled with much cheaper servicing and much less repairs the knock on will be more disposable income so higher taxes elsewhere wont have as much impact.

Gonna be a lot of job losses too - lorry drivers, delivery drivers etc.

having just taken delivery of wife's new 999cc, 3 cylinder turbo petrol yesterday I can say that I am mightily impressed with the engine. We traded in a 7 yr old 1.6 'normal' petrol Kia Soul. The new car (Q2) is significantly nippier, with an immediate pickup from low revs and was still pulling well at 60 mph when I slowed down 🙂 It doesn't really feel significantly less torquey than my big DSG diesel estate. Over the 40 miles it did yesterday from rolling out the dealership, on urban roads, it was showing 46 mpg.