Low-carbon alternatives to diesel are needed to reduce the carbon intensity of the transport, agriculture, and off-grid power generation sectors, where compression ignition (CI) engines are commonly used. Acid-catalysed alcoholysis produces a potentially tailorable low-carbon advanced biofuel blend comprised of mixtures of an alkyl levulinate, a dialkyl ether, and the starting alcohol. In this study, model mixtures based on products expected from the use of n-butanol (butyl-based blends) as a starting alcohol, were blended with diesel and tested in a Yanmar L100V single-cylinder CI engine. Blends were formulated to meet the flash point, density, and kinematic viscosity limits of fuel standards for diesel EN 590 (on-road), and the 2022 version of BS 2869 (off-road). No changes to the engine set-up were made, hence testing the biofuel blends for their potential as “drop-in” fuels. Changes in engine performance and emissions were determined for a range of diesel/biofuel blends and compared to a pure diesel baseline. The ratio of butyl-based biofuel componentsblends contained ranged 65 – 90 vol% n-butyl levulinate, 5 – 10 vol% n-butanol, and 5 – 30 vol% di-n-butyl ether. Formulating the blends to match physical property limits ensured the engine operation was not significantly influenced by changes in these selected properties. Emissions of CO, NOX, total hydrocarbons (THC), and PM2.5 and particle number (PN) size distributions were measured. Compared to the baseline diesel, ignition delay times were longer following the addition of all of the tested biofuel blends. The brake-specific fuel consumption of some butyl-based blends at high loads was close to the diesel baseline, with changes below 5%. Most blends caused a less than 3% reduction in peak in-cylinder pressure at high loads, which contributed to maintaining engine efficiency. PM2.5 and PN emissions reduced significantly upon addition of the biofuel blends. Although at the highest engine loads some reductions were seen for CO and THC, specific emissions increased relative to diesel for all blends, potentially due to their reduced derived cetane number relative to diesel. This however, resulted in increased premixed combustion favouring reductions in particulate emissions. Changes in adiabatic flame temperatures and charge cooling effects, contributed to maintaining blend NOX emissions close to those of diesel. The performance of several butyl-based blends demonstrated that they may have the potential to contribute to carbon reductions in applications using CI engines, as they matched the performance of diesel but exhaust after treatment systems may be needed to counter any changes in emissions.