Should you be concerned about the ethanol limit in petrol increasing potentially to 10%? Rob Marshall wades through the propaganda to discover how E10 might affect the typical motorist.
The proclamation that the UK government will ban new combustion-powered cars and vans from 2040 was a statement of intent to slash CO2 from road transport. The subsequent announcement (that, curiously, was followed by a consultation) on whether the date could be brought back to 2035, or earlier, seemed somewhat premature, especially when there is no clear step-by-step strategy through which alternatives can be introduced.
Similar concerns involve introducing E10 petrol, which contains up to 10% ethanol, compared to the current 5%. While a Call for Evidence was presented in 2018, close examination of the current consultation’s documents (on which comments are welcomed until April
19th www.gov.uk/government/ consultations/introducing-e10-petrol) suggests that the UK Government is not necessarily asking “should we introduce E10 petrol?” but “how should we introduce E10 petrol?” Even so, The Department for Transport (DFT) told CM that no formal decision has been made about whether, or not, to introduce E10 at the time of writing. However, it seems very likely. One reason is considerable lobbying by the British bio-ethanol industry, which has an obvious agenda. Yet, it is worrying that hardly any work has been done to investigate how E10 will affect the average British motorist. As an example, the Institute of Mechanical Engineers is one body that has recommended the government to roll-out E10 – but it admitted to CM that has not done any research on whether, or not, the new ‘eco-fuel’ will damage cars. This article hopes to restore a degree of balance.
The latest updates
2018’s public ‘call for evidence’ on
E10 was part of an exercise to collate information and educate motorists about petrol (and diesel) bio-fuel content, should E10 be launched formally. One reason might be to avoid a repeat of the disastrous and almost hysterical boycotting of E10, when it was introduced in Germany nine years ago. This is a benefit of last year’s fuel pump relabelling exercise, to highlight and familiarise the public with the fuels’ bio-fuel content, even though the change was necessary to comply with European Directives on labelling standardisation.
It is worth noting that a number of EU countries have adopted E10 but, currently, UK petrol retains ‘E5’, meaning that our petrol contains a maximum of 5% ethanol, although 3-4% is reputed to be a more realistic average. While E10 is popular on the continent, it is also especially prevalent in North America, incidentally.
The environmental reasoning
Ethanol was blended with UK petrol during the Noughties as a renewable addition to help reduce reliance on fossil fuels and make road transport a little ‘greener’. Today, even when excluding aviation and shipping, the transport sector is responsible for over a quarter of the UK’S total CO2 emissions. Therefore, the government wants to slash the figure, especially since Theresa May committed Britain legally to achieve net-zero carbon emissions by 2050, before her teary resignation from No 10 last summer.
Despite electric vehicle sales growing, the uptake is insufficient to provide a shortterm answer. Increasing petrol’s ethanol content is a sure way to reduce the carbon dioxide figures, that is, according to the bio-ethanol industry that is pushing the government for E10’s rollout, to ensure its commercial survival. However, when a leading bio-fuels proponent told CM that ethanol is ‘innocuous’ in the real world, we had to dig a little deeper to discover if that assertion is true.
Smoke and mirrors?
If ethanol-blended fuels were harmless, why would the respected German motoring organisation, ADAC, report that a single tankful “can cause serious, lasting damage”, if used in a non-compatible vehicle, a view that is shared by a number of carmakers? In E10’s defence, it does not ruin engines. In 1981, the North American Journal of Automotive Engineers ran several new 2.3-litre petrol units for 20 hours under mid-load conditions and concluded that E10 did not increase engine wear levels significantly, compared to regular US unleaded gasoline of the time. While greater water content in the oil, plus slightly elevated levels of camshaft follower, valve guide and No.2 piston ring wear, were noted post-test, these were not significant.
While CM is unaware of any laboratory tests conducted more recently on modern engines, with their tighter tolerances, different materials and new lubricant and petrol compositions, it still seems unlikely that E10 harms engines directly. Ethanol can still cause damage indirectly, by
affecting the fuel injection, inlet and lubrication systems, however. It is the reduced capacity of these systems to work at their optimum efficiency that causes premature engine wear, along with higher fuel consumption and emissions, that undermine E10’s environmental credentials.
While direct fuel injection (GDI) raised engine efficiency and reduced CO2 outputs, a downside was that the more precise, high-pressure fuel injection components became less tolerant of deviating fuel specifications. Early GDI engines from the Noughties are likely to be harmed by E10, with the aluminium components inside the expensive highpressure fuel pumps especially at risk of corrosion attack, triggered from the first time E10 is used and cannot be stopped.
In 2011, ADAC found that a brand-new high-pressure fuel pump of its E10incompatible 2.2-litre Opel/vauxhall Signum test vehicle failed after only 27,000 kilometres of running on petrol containing 10% ethanol. Interestingly, the Volkswagen Group’s first-generation FSI engine is the most common non-e10 compatible vehicle on UK roads.
While the DFT directed us to its tests, carried-out on vehicles running on E10, we noticed that the cars used were virtually new and, therefore, are unrepresentative of an average car on British roads. The DFT responded that new car models are Type Approved tested for emissions and fuel consumption results in Europe using E10. Yet, it could neither confirm if E10 was used as a reference fuel to Type Approve older cars of average age in the UK (standing at almost eight years), nor if it had conducted any research about the effects of E10 on such vehicles that experience British climates and drive-cycles.
Fighting increased deposits at the top
According to the AMF (Advanced Motor Fuels), E10 contains sulphates and copper that introduce gum formation and promote fuel injector deposits. JLM Lubricants of the Netherlands highlights that, aside from acting as fuel, petrol possesses a lubrication quality but, because ethanol lacks such properties, the durability of fuel system components could be reduced, unless extra additives are blended with the fuel at the refinery to counteract the problem. Consider also that ethanol is hygroscopic and can hold water in suspension, enhancing the risk of corrosion within the fuel system.
From its experience of the North American market, BG Products reports that the additional oxygen present within E10 accelerates the fuel’s ageing process. This causes, what the company calls, ‘damaging deposits’ being formed post-combustion that it states are caused typically by ethanol. ITW Additives International, makers of the renowned Wynn’s and Forté ranges, concurred and told us that ethanolblended petrol tends to be more acidic. The resultant incomplete combustion causes more deposits to be circulated via the exhaust gas recirculation (EGR) and the intake systems. Consequences include higher exhaust emissions, poor running, catalytic converter failure, sticking inlet valves, plus EGR valve/ swirl-flap blockages/restrictions.
Fighting deposits at the bottom
According to the Royal Society of Chemistry, as bioethanol is blended with gasoline at increasingly higher concentrations, the build-up of fuel in the crankcase/sump could be significant. Therefore, engine oils must combat ethanol’s tendency to compromise a vehicle’s lubrication system.
David Wright, Director General of the Uk-based Verification of Lubrication Specifications (VLS) adds that, because biofuels are less stable than other fuels
and oxidise easily, increased engine oil thickening results, which restricts lubricant flow.
While Lucas Oil of North America states that much of the fuel that enters the sump evaporates at higher temperatures via the crankcase breather, ITW Additives International states that this is harder for E10, due to its ethanol content, which can hasten engine oil deterioration. Lucas Oil agrees, but adds that ethanol does not mix thoroughly in motor oil. In theory, therefore, higher levels of oil dilution from the fuel could allow sliding metal parts to be exposed to surfaces wet with ethanol, instead of lubricant.
While it is well-established that short journeys, low coolant/oil temperatures and skipped servicing increase oil deposits, ITW reports that engine sludge could become more prevalent, should the ethanol content in UK petrol be increased. Oliver Kuhn, deputy head of LIQUI MOLY’S oil laboratory in Germany, highlights that Hybrid vehicles may suffer especially from increased deposits in their oil, because their E10-fuelled combustion engines tend to be run less frequently at higher temperatures.
LIQUI MOLY adds that ethanol’s 4% water content forms more acids, which decreases engine oil ph values and reduces viscosity and shortens its life. While this sounds alarming, both Mr Kuhn and Mr Wright agree that these issues should not pose a problem for modern engine oils, because the latest lubricants are formulated to address these technical challenges for petrol containing up to 20% ethanol. However, as Mr Wright revealed that older lubricant formulations are designed for fuels that were available at that time of their development, it is possible that these blends cannot withstand premature degradation, should E10 be used. Additionally, LIQUI MOLY’S research also uncovered engine oils that do not comply with the updated specifications for E10. Naturally, using more ‘ethanol resistant’ oil that possesses a thinner viscosity in an older engine could cause severe damage, just as using older specification lubricants in newer engines is just as unwise.
Short shelf life: Phase separation
As E10 degrades, typically within 4-6 weeks after refining, the ethanol absorbs and holds water in suspension up to a certain level, prior to phase separation occurring. The rate at which it does so depends on atmospheric conditions.
The condition makes an incombustible water-ethanol gloop fall to the bottom of the tank, leaving a low-octane petrol layer above it. Even if a modern engine can start and run on this aged and degraded fuel, lacquer and varnish deposits are likely to affect fuel injector spray patterns, leading to incomplete combustion and the accumulation of even more deposits, let alone worsening exhaust emissions. Low mileage users that do not replenish their fuel regularly are especially at risk.
Yet, modern Plug-in Hybrids can suffer too, because they are more likely to retain the same tank of fuel, due to their ability to be driven short-distances on electric power only. Brimming and emptying the petrol tank regularly before the fuel ‘goes off ’ might not be a viable option in those cases. Interestingly, the Chevrolet Volt/vauxhall Ampera hybrid models (sold as the same car under different badges between 20122014 but, admittedly, were not volume sellers in the UK) had a fortuitous fuel maintenance mode to use-up stale fuel but it activates only after a year has elapsed from the last fuel fill-up.
A number of our sources acknowledge that driving styles and conditions influence the technical challenges that
E10 brings. While we are aware that a bio-fuel supporter advised the DFT that UK real-world tests were unnecessary on E10, because “the Americans, French, Belgians and Finns have done it for us”, it presumes that overseas climates, driving habits and road conditions are the same as ours. While France constitutes the largest E10 market in the EU, with 38.5% of petrol sales; that figure plummets to 13.4% in Germany (based on 2017 figures). Therefore, it is possible that real-world technical issues, attributable to E10, may not be prevalent as those experienced in North America, where 95% of gasoline there contains at least 10% ethanol.
Yet, comparing US conditions directly with the UK is also difficult. BG Products has bases in both the UK and North America and revealed that it found average UK mileage to be 7,400 annually, compared to 13,400 in the US and, because US passenger car fuel tank capacities tend to be smaller than those in the UK (and EU), it is not an unreasonable presumption that North American tanks are replenished nearly twice as frequently, which would make them less susceptible to phase-separation. Several sources also revealed that North American drivers tend to change their oil more
often (it can be as low as every 3,000 miles but tends to be around 7-10,000 miles, or twice annually), compared to the recommended drain intervals of between 10,000 and 20,000 in the UK/EU, or once annually.
Should E10 be introduced, what can you do?
It is worth noting that your fuel consumption is likely to increase by around 1.5% on E10, compared with
E5, and there has been no indication so far that the new fuel will attract a tax break. Even so, this article is not debating E10’s introduction but to highlight technical challenges that are relevant for the typical British motorist. Should your car be non-e10-compliant, do not be tempted to fill-up with it. Should your car be approved, consider fuel deteriorates issues. Keep the tank’s contents ‘fresh’ with regular fill-ups, which should help to reduce the waterabsorption and phase-separate risks.
As E10 is likely to increase deposits within the engine oil, take further action at service time. Ensure that the crankcase breathing equipment is in good condition and use a quality flush at every oil change (See CM’S February
2020 issue). Lucas Oil in North America advises CM’S UK readers to consider more frequent oil changes too, and make minor adjustments in driving habits, such as consolidating several small trips into fewer longer ones. Using a fuel additive at service time, to help combat fuel injector lacquering, is a useful preventative measure, as is monitoring both intake and EGR systems for increased deposits.
We must emphasise again that the DFT has made no formal decision on E10’s introduction. However, as the practical in-service issues of E10 appear not to
have been discussed in-depth by our policymakers, at the time of writing, the technically-aware owner needs to be better informed of the potential issues that E10 can cause. We hope also that government advisers will take into consideration the environmental influence of potentially decreased older engine efficiency, the increased need for flushes and additives, plus greater oil change frequencies in their CO2 calculations. We have agreed to supply the DFT with some of our research, before it reaches a verdict on E10’s British future.
New petrol labelling from last summer highlights bio-fuel content.
Classic cars are not the only vehicles affected by E10. The most prevalent known family of engines that are E10-incompatible is Volkswagen Group’s FSI range.
Be wary of presuming that a range of cars is E10 compliant, because there can be exceptions. Volvo, for example, states that its post-1976 cars can be run on E10, except for 1.8-litre GDI variants of its V40 and S40 models, which were made until 2004.
Unless resolved by the fuel blenders, E10 phase separation could become a severe issue for stored cars and low mileage users – and also current Plug-in Hybrid vehicles. This Mitsubishi Outlander PHEV can be driven up to 28 miles in electric-only mode, according to the stricter realworld WLTP tests, meaning that the same fuel could be in the tank for many weeks, or more.
While GDI engines are prone to intake contamination, E10 is known to increase the rate at which these deposits build.
Due to the different combustion chemistry, the power output of ethanol is slightly lower than of petrol, so fuel consumption increases slightly. Yet, the difference between E5 to E10 petrol is barely noticeable. ADAC has calculated that the typical motorist will have a fuel consumption increase of approximately 1.5%.