One of the fun things about researching articles is how you can end up in a totally different place than where you started. A few weeks ago, I was working on a story for the October issue of HDT on oil and coolant analysis. That led to what I'm going to talk about today, which is fans and fuel economy.
It started out when I was talking to Mike Tourville with Evans, which makes a waterless coolant. The first time I heard of it, I thought maybe it was some sort of a powder. Common reaction, Tourville said, but Evans' product is indeed a liquid - in fact it looks a bit like the color of iced tea.
'Powder does seem funny, but you aren't the only one, as we've heard that before,' Tourville said. 'More often people have asked if it's a gel. One guy asked if it was 'a bunch of little fans everywhere.' Waterless doesn't mean 'liquidless,' but it's an initial perception.'
Unlike traditional coolants, none of that liquid is water. It's all a blend of glycols and the necessary additives to protect the cooling system (although you don't need some of the same additives that protect against what water can do to the system.)
Because its Heavy Duty Coolant has a boiling point about 150 degrees higher than that of coolants with water, Evans contends, the coolant allows the engine to run a bit hotter. That, in turn, allows you to up temperature where the fan kicks on, reducing fan-on time, and that translates into fuel savings.
Tourville says the company is seeing 3% to 8% fuel economy improvement in real-world testing with owner-operators and fleets. At the upper end of that are inner city trucks, such as refuse trucks, which don't get much in the way of ram air to cool engines. The Evans coolant allows them to reduce their fan-on time by 40% to 50%. For an over-the-road trucker, where speeds going down the road allow the air to help cool the engine, the savings would be closer to the bottom of that range at 3%. Veolia is getting about 4.5% fuel economy improvement in their Macks.