I have been considering buying a new mid-size diesel saloon, mostly for business use, and I’m concerned about the inconvenience and cost of AdBlue additive, having read some fairly alarming reports. It seems that the tanks are often quite small, (9 litres on a Jaguar XE, although 17 litres on an XF) and that means you could (according to Jaguar) need an AdBlue top-up as often as every 5,000 miles. You would have thought that they would have given them the ability to last between normal service intervals, say 15,000 miles, so you didn’t have to worry, and could just have your AdBlue refilled then. Do all cars in a similar market grouping, like executive saloons, use the same amount of AdBlue, and do any of them have larger tanks than others, that might help avoid the inconvenience of more frequent top-ups?
Well Tom, I don’t think that you are going to find any significant differences between manufacturer and model AdBlue tank sizes, or at least the effective range of a tankful, to sway you to one or another. You may even have read that there was, it is alleged, some kind of mutual agreement between competing German manufacturers regarding the size of their AdBlue tanks. The net effect of this was probably to stay in line, and not attempt to offer significantly larger tanks that would totally avoid the need for between-service top-ups. The tank sizes are by no means standardised, but you will find that most manufacturers suggest that the tank size equates to around 5,000 miles of normal motoring, which might mean one or two top-ups between service times, which is hardly onerous.
You also get plenty of warning when the tanks starts to run low, and in most cases it can be a DIY job, or you can pop along to your dealer for a quick fill-up, probably instantly if you call ahead by phone. What I would say (and BMW have a useful calculator that works out how often you are likely to need a fill up, see infodiesel.co.uk/adblue-bmw/bmw-5-series-saloon/) is that top-up intervals very much depend on how you drive and what sort of motoring you do. Long runs on the motorway, without much aggressive driving, will use less AdBlue, and I have read of owners who have gone to 20,000 miles and beyond on a tankful. In contrast, short local stop-start runs will drag the mileage down to the 5,000 to 10,000 miles that seems to be more typical, and in line with a typical usage of a litre of AdBlue every 500 to 600 miles, although you should bear in mind that usage (and tank size) depends on engine size, and something with a 3.0-litre engine will use more than a 2.0-litre. I should also point out that heavy SUVs will probably use more AdBlue (and more diesel, for that matter!) than an executive saloon.
Some car makers, like Audi, do offer a no-cost upgrade to the size of the AdBlue tank. For example, on the A4 the tank size is usually 12 litres, but can be increased to 24 litres for free. No doubt that these smaller tanks are all designed to reduce weight, which in turn improves economy and lowers emissions, although does nothing for convenience to the customer.
Hope this hopes your deliberations, but I would encourage you to grill the dealer staff about the AdBlue system on any given car you’re considering. From what I’ve gathered, sales people are possibly sent on training courses on ìHow to avoid talking about AdBlueî and leave it to new owners to discover the facts themselves! Best regards,