Gerrycan

The 1.4tsi Octavia available in Australia is not available with the manual box and the auto is an Aisin torque converter which I am not keen on. However a few weeks ago I went in the local dealer while servicing on my old mk3 1.4tsi and saw a white manual 1.5tsi Scala which I was very tempted to put a deposit on there and then. A modicum of common sense (maybe a fear of wife?) prevailed and I attempted to first arrange a test drive for us. A dsg Monte Carlo version available to test, which was really not going to be good enough, so the moment was lost, although not entirely abandoned. I presume the Scala has the same ratios as the Octavia 4 so it interesting to read of such differing characteristics between 1.4tsi and 1.5tsi. My opinion of the 1.4tsi is that it is a really good flexible engine which pulls from low revs but still happily revs up to the red line. Great performance and economy. At 70mph in 6th gear it is revving at 2700rpm and it is quite possible to accelerate up relatively steep long hills without changing down, although I usually display a little mechanical sympathy and change down to 5th. I believe the 7 speed dsg box is geared to 2500rpm for the 1.4tsi. I did feel the gearing could have been lower in 6th for at least a reduction to 2200rpm. I'm confident both engines deliver the same specified power and torque but there may be a little more at play than just the gearing affecting the apparent lower performance of the 1.5tsi. The new engine has ACT and a different type of turbo (variable) and the emphasis of the new engine is lower consumption and emissions which quite honestly seems to have been a problem for VW to meet with good driving characteristics. I believe the eco ACT cuts in above 1400rpm and below 30% max torque so if you press the accelerator it is quite possible the 1.5tsi throttle mapping is less sensitive to allow some acceleration and still run more economically on two cylinders. That is purely speculation of course. I'm sure that using a bit more welly with 1.5tsi in the appropriate gear will get things moving for easy overtaking. Having read this thread I am keen to again get a manual Scala test drive arranged for us. I have only once driven a long geared manual and that was a diesel Kia C'eed we hired on a UK visit about 4 years ago. We did a LOT of motorway driving and I was pleased with the initial 60mpg returns on refills but when I twigged how long the gearing was and that the diesel had a sudden torque hole at lower revs I changed my style and the last two tanks gave actuals of 70mpg. I did this by ignoring the displays gear advice and not loading the engine using to low a gear, so had to be doing over 60mph for 6th, over 50mph for 5th, over 40mph for 4th and so on. A lot more gear changing, slightly higher revs but still on small throttle settings and things were much happier. Would be interesting to see if the 1.5tsi manual responds similarly. Trouble is my wife is a bit more of a lead foot than I am and likes the 1.4tsi characteristics so that's why the test drive is important. Very few Australian women are happy to drive manuals so she is still a 'keeper' whatever she decides

If you compare the calorific values for diesel, petrol and ethanol by the traditional sales system of volume (litres/gallons) then petrol has 10% less than diesel and ethanol 30% less than petrol. If you compare them by weight (kilograms/pounds) then there is far less difference. Aromatics are usually added to petrol to achieve regulation anti-knock ratings but they are not without problems: Fuel left in a tank will usually degrade over a period (beyond 6 weeks) as the more volatile aromatics deteriorate/evaporate so your RON rating will reduce which can affect how well the engine performs. The aromatics are not without their environmental issues. In Australia they were also a real problem for remote aboriginal communities where the youth engaged in petrol sniffing highs resulting in permanent brain damage or death from the Aromatics. A special low aromatic 91 RON fuel is now sold in those areas (I believe it is methanol based) Pure ethanol has a relatively high 109 RON rating so it can be mixed with petrol to replace some aromatics to achieve regulation RON ratings, but it is not without its problems: Ethanol is more corrosive on older incompatible tank linings, seals and fuel lines, but most modern engines are designed to accommodate at least 10% Ethanol content. Ethanol is quite hydroscopic and will attract water more than petrol. If this is allowed to happen through poor storage/transport then the ethanol will separate from the petrol and the engine will run very poorly as it runs on either the lowered octane petrol or the ethanol/water mix. Ethanol mixed with petrol will reduce the calorific content, with a 10% mix by roughly 3% although in Australia when mixed with 91 Ron petrol it raises it to 94 RON. Ethanol is usually touted as a 'green' fuel as it is made from renewable resources. This claim stands up to examination where they use a waste resource to produce ethanol but less so where good agricultural land is used or virgin Amazon rainforest is destroyed to produce the source material. Australian E10 is marginally cheaper than pure petrol but has developed a very poor reputation as there have been many cases where independent testing has shown the ethanol content to vary considerably between batches and storage/transport is below acceptable standards especially for humid conditions by the lower tier producers. The major reputable petrol companies here have had little involvement in the addition of Ethanol to their products, although that will change with future legislation which should improve the product reputation. I'm sure these aspects will already be better controlled in the UK and Europe by your suppliers. E85 (105 RON) is available at some stations here but as far as I know there was only one, now defunct local manufacturer (Holden), who made a 'Flexfuel' engine capable of running it. Unfortunately the engine was designed to run on petrol or the Ethanol mix so was not optimised for either and each fuel has completely different characteristics. The 15% petrol in E85 is required because pure ethanol is otherwise quite difficult to ignite.

Might as well put some Hydroxychloroquine in the tank while you are at it. 🤣 Sorry, but I am not a believer. Our 17 yo Toyota with 194,000 km on the clock, an untouched engine and runs on some of the worst fuel in the world, can still meet the official fuel consumption standards without any additives.

You did not mention how much fuel you put in after achieving your 480 miles. The simple way to determine how accurate your reported consumption is to calculate at refill but 45 litres is 9.9 gallons so your actual would be 48.5 mpg if 45 litres went in. The tank size is officially 50L in the mk3 and in probably a bit larger than that (closer to 55L). Never a good idea to run out of fuel though Lots of reports/complaints from diesels owners over the years that they are being prompted to refill by light/gauge/zero distance to empty and only getting circa 40 litres in. If you are being prompted at 45 litres then I'd consider that as liveable. The vRS 190 was never reported in this forum as being quite as economical as the 2.0L 150bhp version but from memory most reported about 50 to 55 mpg. You don't mention the car's mileage which might give an idea of how it has been used over the last 7 years. If I were you I'd get a cheap OBDC dongle and the DPF app on your phone to monitor ash content and regen frequency. An Italian tune-up now and then when warmed up (in a quiet, unmonitored spot) might not do any harm to long term mileage either.

60mpg at 60mph average is very good for a petrol engine and the 1.0tsi is a comparatively efficient unit but based on my limited experience of driving on UK motorways, I think it is about right in near ideal temps. If you are a naturally economical driver who does not brake much then I don't think the 48volt mild hybrid system would have contributed very much to your results. I see no reason why you will not get similar consumption, maybe better, from your manual 1.5tsi (with cylinder deactivation) in similar circumstances. The mk4 has exceptional aerodynamics for its class and that has got to help at higher average speeds.

With older VW group engines where they specifically recommended a higher octane fuel then I can understand a benefit, but I think the story is less clear with present production engines which are expected to meet rigid emission requirements. Within the context of a standard vRS on a rolling road there may be a small increase in power using a higher RON but just how much? Mazda make a 2.5L turbo 'SkyActive' engine for which they issue power figures with different RON ratings. It can be run on our Australian obnoxious high sulphur 91 Octane rated fuel, which is a miracle in itself considering their engine's high compression ratios but they also say that if run on 98 Octane fuel it produces 13kw (27bhp) more power, however the max torque is unaffected. Unfortunately they do not give figures for 95 RON but my guess the power figure is closer to the 98 RON than the 91 RON so the difference is probably quite small. Another story comes from a now retired research auto engineer in the Fabia 3 section, where he was involved in independent testing of a range of currently available production small turbo engines from various manufacturers with 95 and 98 rated fuels. IF I remember it correctly their findings were that most engines had been so optimised for 95 RON fuels that there were little to no benefits in running the higher octane for power or overall consumption, AND for some engines there was actually a measurable but marginal decrease in both. The owners manual for our 2003 1.3L Toyota Echo states with remarkable frankness that the engine is designed for our local 91 RON fuel and there is no benefit in using a higher octane, so I don't. The engine has done 194k km and never been touched apart from irregular servicing and can still return 55mpg on a refill if I can string together a few runs longer than 10km. It is all a great pub discussion point though.

Pretty sure that all Euro mandatory emission and consumption regulations are required to be met with 95 Ron. No idea whether that would apply to published power figures but considering how easy it is to boost power outputs from software changes why would they resort to 'special' petrol.

I find opening any single window causes a very uncomfortable and unbearable beat in the car, even at remarkably low speeds. We have a Mk 3 Octavia estate and for me the only thing that works is to open a front window and a diagonally opposite rear window. Experiment with the amount the windows need to be lowered to get the required airflow. Funnily enough this was the recommendation from a recent (British I think) study to get the best airflow in a car to reduce to risks of Covid transfer.

The F word is the classic reaction by those who have have subsequently reported one or more transport blocks being left in the front suspension. They can only usually be exposed by jacking up the front enough to allow the suspension to 'droop'. Make sure you are present when the inspection is made and if they are discovered to be present suggest they owe you some recompense for your inconvenience, distress and potential safety issues from the poor handling.

@wr0na, a really frank and interesting review both from the perspective of the use of an EV for long distance travel and the way it was conducted. I'm presuming you were operating roughly in the 20% to 80% battery capacity range to maximise charge rate and minimise time spent at the stop so I'm estimating with your 1:10h at nominal 160kph motorway driving speeds you were maybe getting between 150 to 180km between charges? Roughly how many times and how long did you have to wait for an available charge station? We are in the very early stages of EV adoption here in Australia and the choice of EV are limited, numbers on the road are low but growing, and the recharging infrastructure very patchy in some areas so your experience gives some idea of what's to come and potential issues. I think it is going to be about 5 years before the sort of affordable vehicle I want is available here and an infrastructure in place to support it. Or I get a PHEV?

Manufacturers nowadays have to build an internal combustion engine that complies with emission regulations and customer performance/price expectations and that means at some point there is usually a compromise. A remap or plug-in box will usually release additional performance and my guess is that emissions are a much lower priority so it would not surprise me if there is a small potential improvement in consumption achievable if the extra power is not utilised. Plug-ins tend to corrupt the consumption displays so appear much more economical than they really are. 'Dieselgate' was a classic example of a manufacturer resorting to cheating to meet cost/emission/performance targets and when the subsequent software emission fixes were applied there were many stories of poorer consumption/performance/reliability from lots of unhappy people. Also in 2014 the 1.4tsi 103kw in my Octavia was officially marginally more economical than the equivalent 90kw version of the engine. Do not expect the cost of a remap to be paid back with better consumption in the lifetime of the vehicle.

I always thought it was not so much the coasting downhill that was dangerous but actually switching the engine off as well while doing it where you'd probably lose brake and steering assist in that generation of vehicles. Kill switches (totally illegal) are popular with manic US hypermilers. I have a manual and I'll admit to coasting in neutral where I think it's safe and I will get a consumption benefit, but often as not I'll do as well or better leaving it in gear and using the minimal engine braking effect on offer where fuel is cut off and opposed to the minimal fuel (0.5L/hour in my 1.4tsi) used by an idling engine when coasting. It's been a part of how I drive for so long I'll probably miss the challenge of driving economically when I eventually get an EV. Pre-Covid, my wife and I were looking at a possible awd Kodiaq purchase for a round Australia trip, but I was hoping for a bit better than the 45mpg you are getting on a run because while our fuel can be cheaper, the distances are a bit daunting. Not sure I would get much better than that from any (suitable) awd though.

@BoxerBoy realistically the bi-turbo diesel awd kodiaq is a large heavy vehicle with relatively poor aerodynamics so it is not something you buy for its low consumption especially if you like to use the performance on offer when circumstances permit. I reckon anything over 40mpg is not bad for the vehicle type. I can understand how annoying the coasting feature would be driving around Scotland as engine braking is a useful thing in hilly terrain. My small petrol engine Octavia offers virtually no engine braking and while that is not a problem on the flat terrain where I live, a trip to Tasmania (parts are similar to the Scottish Highlands) a couple of years ago really highlighted how much I missed its contribution. Does the coasting 'turn off' if you touch the brakes?

I'd be surprised if extended idling causes damage to the engine. However if the DPF does go into regen mode then the revs will rise and fuel pumped into the catalyst to raise the temperature to over 400 deg C to burn off the accumulated carbon. There may may well be a smell in the cabin and if you have parked on dry grass then there is the risk of fire from the hot exhaust. May sound spectacularly alarmist but it happened to a BMW diesel police car here in Australia. They had stopped a speeding car and left their engine running having pulled over off the road while they 'interviewed' the speedster and then looked back to see their A$150k car in flames and eventually gutted. I tend to agree that what you are doing sounds hardly best parenting practice. Then again I was useless at it but my wife was brilliant at bringing up our two

What engine are we talking about?

That is the first time I have seen anyone confirm in this forum the 1.4tsi 140bhp fuel standards as 95 RON and 91 RON emergency. Australian fuels are a somewhat unique mix. We have a 91RON (max 150ppm sulphur), 95 and 98 RON (max 40ppm sulphur), E10 and E85 and in the outback a special 91 RON substitute called 'Opal'. The manual and filler cap of my car just says 95RON minimum recommended but I was advised by the dealer early in the ownership to run it on 98RON. I tried a few concurrent tanks of 98 but did not detect any improvement in response or economy so I went back to using the cheaper 95 RON which mine is happy on. I shudder at the thought of putting our 91 RON in. The E10 is a couple of cents a litre cheaper than 91RON and used to be advertised as having a 94RON rating, which would make sense with the ethanol added to the 91RON, but this advertised rating has been dropped. I recently had a look at an E10 bowser and it had a small sticker attached saying that Ethanol content could vary between 0 and 10%!!! Pretty much a backyard operation it seems. Ironically our government has deemed our last two or three remaining refineries to be strategic assets and have agreed to pay the owners an extortionate amount to stay open and upgrade their facilities to meet EU 10ppm sulphur content standards. It could also mean that 91RON is dropped and 95RON is achieved with 10% ethanol as per the EU and UK. Very few road cars can run the E85 ( it was a short fad for Holden, one of our now closed car manufacturers) and they are not optimised for it so they cannot really use the 105RON rating effectively and consumption is reported as being unusually bad although power seems not to be a problem. There are a couple of local racing categories that specify it and the engines are tuned solely for it. 'Opal' is a BP product with a low 5% aromatics (Tuolene etc) content to combat the incredibly damaging effects of petrol sniffing in aboriginal communities, and it has worked. Expensive to produce but it is subsidised at 33c/litre by our Government. I've seen literature suggesting that engines running it develop far less carbon deposits than standard 91RON but it is not available in metropolitan areas otherwise I'd put some in my 25 year old lawnmower.

Was that fitting the spare, or all tyres, or having the (front) wheel tracking done? The 16" spacesaver (Nexen) tyre on my car is incredibly and unbearably noisy when fitted Have you tried switching the tyres diagonally back to front to see if anything changes at all with the reversal of tread?

The 1.4tsi Octavia does not have irs rear suspension it has a torsion beam rear. My understanding is that there is nothing they can adjust but I could be wrong. IF I'm right then it suggests the back has taken a knock which may require a new part to correct the misalignment?

@themanwithnoaim ran a DTUK box on his 1.4tsi DSG for a few years with no problems. His average 30mpg consumption was confirmation of his 'drive it like you stole it' approach. The turbo is relatively small to boost low down torque and that aspect is accentuated by a remap according to 'tmwna' so there was little benefit in revving to the redline. I know he moved onto vehicles more appropriate to his driving philosophy so we haven't heard much from him lately.

The SUV shape is very fashionable at the moment and fashion is not necessarily sensible, think high-heels, flared trousers or smoking The Achilles heel of the SUV shape is the large frontal area and relatively poor drag coefficient. The Enyaq is quoted at 0.27 whereas the mk4 Octavia sedan is 0.25 and that is despite including a possible 30% penalty for the ICE engine radiator. You would think an EV optimised version of the Octavia sedan would achieve about 0.23 , maybe better? The proposed Mercedes EQS EV is quoted at 0.2 but that efficiency is achieved at the expense of a jelly mould shape, although I personally don't mind it. My ideal EV specification is not yet available: Affordably priced Battery technology more simple and durable than current Lithium tech with no complex cooling/heating requirements for rapid charging, and also lighter than current batteries. Relatively small battery capacity with say a useable 50kWh capacity Efficient aerodynamics and low weight that allow 500km cruising range at 100kph, although capable of cruising at higher speeds (with increased consumption). There are some very interesting new battery chemistries that hold some promise for what I am looking for, but they are a few years from production.

Don't forget insurance.

I'm pretty sure the coolant system for the head and exhaust manifold is temporarily isolated from the rest of the engine by a valve to allow it warm up quickly to operating temp and reduce emissions. Bonus is that it includes the heater matrix so even in winter you get warm air reasonably quickly, however in colder air temperatures turning the heater full on will extend the time it takes the water temp to reach 90 deg when it presumably integrates the whole coolant system. My old 1.9pd seemed to take about 10km in our mild winters before even slightly warm air came out vents, and about 15 minutes to reach 90 deg on the gauge. Engine was too efficient and a lot of iron in the engine block to heat.

I have experienced really bad sawtoothing (unbearable noise) on previous cars which was immediately cured with a change of tyres and 4 wheel realignment (independent rear suspension). My current car has mild sawtoothing (bearable noise levels) but the tyres will soon be due for replacement so I can live with it until then. However the noise and vibration I experienced, while variable on different surfaces and speeds, was/is always present whatever the speed so I'm not totally confident that the OP's speed specific issue is necessarily attributable to tyres . As mentioned previously by someone else, the simple test is to run the hand over the tyres in each direction to feel for variation in the levels between the start/finish of each tread block.

It is a pretty high percentage of the price of a brand new car for ONE headlight and it was just a pigeon I mean if he hit something like an emu then yeah, that could be expensive.

Many years back, when we were looking for a new car (and eventually bought mk2 Octavia), my wife took out a Mondeo for a test drive by herself. She was only doing 60kph limit in the 'fast' lane of an urban multi-lane when a large flock of pigeons flew out of the centre nature strip and she drove straight through them. No damage done to the car fortunately, and my wife was horrified but steered straight. She said the salesman's face said it all when he first saw all the blood and feathers that smothered the front of his brand new demo from a 15 minute test drive. Some years later we discovered there was a local bird fancier who fed them there for years, hence the concentration of birds. He probably remembers it as the 'Great Mondeo Massacre'. I find the costs being quoted for replacing damaged higher spec headlights (xenon, led) does seem extraordinarily high.