Every project car is a clean slate. However, you’re working with a car that’s over 30 years old, like our newly minted Fox Dreams, a 1993 Mustang LX Feature Car convertible, you need to start with the basics. No matter how solid the platform looks on the outside, decades of wear, heat cycles, and fluid degradation can take their toll under the surface.

It makes sense to replace all operating fluids with suitable high-quality products… — Steffen Niemietz, LIQUI MOLY

Before we dove into major upgrades, we paused the horsepower plans to give this classic Fox Mustang a refresh. That meant inspecting and replacing every critical fluid — engine oil, automatic transmission fluid, differential lube, fuel system cleaner, and even power steering fluid with high-performance products from LIQUI MOLY.

This project is more than just another Fox resurrection; it’s a second chance at living the dream. When Melissa Lawrence was 17, she had a limited-edition 1993 Mustang LX that meant the world to her. Sadly, a crash took it off the road for good. Decades later, she received another one for her 45th birthday, and with it, the opportunity to finally build the street-friendly Fox she always wanted — one that makes more than 600 horsepower, but can still serve as family transportation. The long-term plan calls for a Vortech-blown 347 stroker, but first, we’re laying the groundwork by pampering the stock powertrain.

“Using products from a premium brand like LIQUI MOLY ensures that only the highest quality formulations are used, manufactured to the highest standards. This guarantees maximum efficiency and performance,” Steffen Niemietz, Application Engineer at LIQUI MOLY, told us.

Making Changes

“Especially when the maintenance history is unknown, but also when the previous operating conditions are unknown, it makes sense to replace all operating fluids with suitable high-quality products,” Niemietz added. “This ensures that all systems are filled with fresh, fully functional fluids and can work optimally.”

Of course, an engine is nothing without its lifeblood. We chose Leicht­lauf High Tech SAE 5W-40, a fully synthetic, all-season engine oil engineered to provide performance and durability. It offers high-load protection, reduced valvetrain noise, and enhanced wear resistance, which are key traits for keeping our high-mileage 5.0 running strong while we plan for its eventual replacement.

“Leichtlauf High Tech SAE 5W-40 is one of our top-notch oils and exceeds the given Ford requirements for this engine by far,” Niemietz said. “It is herewith guaranteed, that the engine is protected against excessive wear and increased oil consumption even under hard operating conditions.”

We kicked off our project by swapping in a TREMEC TKX five-speed manual transmission from Silver Sport Transmissions. After logging some break-in miles, it was ready for a switch to Top Tec ATF 1100. This modern synthetic fluid is compatible with TREMEC’s requirements and is said to deliver consistent shift feel, excellent shear resistance, and superior thermal stability, which should serve our new gearbox well.

“Top Tec ATF products are our latest generation of automatic transmission fluids, developed to meet the demands of all common automatic transmissions,” Niemietz said. “Their low viscosity combined with an extremely durable additive package guarantees optimal performance and minimal wear in the transmission.”

Full Treatment

Out back, the original 8.8-inch rearend is holding its place until our Moser M88 arrives. To give it the best chance at survival, we drained the gear oil, inspected the gears, and filled it with LIQUI MOLY Hypoid Gear Oil GL5 SAE 85W-90. This mineral-based lube includes extreme-pressure additives that guard against metal-to-metal contact under load.

“On the one hand, this oil complies with the manufacturer’s specifications for this system, and on the other hand, the formulation is very pressure- and shear-stable, which ensures minimal wear even under high loads,” Niemietz said.

Out back, we removed the rear cover on the 8.8-inch axle to fully flush the old fluid and inspect the gears. After resealing the cover, we filled the rearend with Hypoid Gear Oil GL5 SAE 85W-90. This mineral-based gear lube includes extreme-pressure additives to protect ring and pinion gearsets from scoring under high torque loads, especially during launches and low-speed turns, which will keep it in great shape until we swap in a robust replacement.

With the original 5.0-liter V-8 still under the hood of Fox Dreams, we started by treating the fuel system with LIQUI MOLY Pro-Line Gasoline System Cleaner. This concentrated additive works to clean injectors, valves, and combustion chambers, which is said to improve fuel atomization and combustion efficiency. It should help clean up any gunk that built up in Fox Dreams over the past decades while improving the engine’s throttle response and overall performance.

“Pro-Line Gasoline System Cleaner is a highly concentrated fuel system cleaner,” Niemietz explained. “Within a single use period (Ideally, one tankful), it removes performance-reducing and wear-promoting deposits, restoring engine efficiency and performance.”

We started by pouring a full can of LIQUI MOLY Pro-Line Gasoline System Cleaner into the fuel tank. This concentrated additive works during combustion to dissolve carbon buildup on the intake valves, injector tips, and in the combustion chamber, which helps on an older engine destined for more power.

This stage of the project isn’t a flashy one, but it’s part of the long-term outlook for Fox Dreams. A full fluid refresh resets the clock on every major system and provides peace of mind as we prepare for the serious upgrades ahead, so stay tuned.