Car Model History

Convertible · 5.0L High-Output EFI V8

1991 Ford Mustang LX 5.0L Convertible 4AT

Ford's 1991 brochure pairs the LX 5.0L convertible with the 5.0L High-Output EFI V8 and 4-speed automatic overdrive.

1991 Ford Mustang (Fox-body) — green LX 5.0 coupe, right side profile
Exact 1991 Mustang reference photograph; exact configuration not verified ·

Photo: TJKula / Wikimedia Commons, licensed under CC BY 4.0. Cropped to 16:9.

Factory configuration

What this model is

Trim
LX 5.0L
Body style
Convertible
Engine
5.0L High-Output EFI V8
Transmission
4-speed automatic overdrive

United States factory configuration. Appearance and value packages are not separate configurations.

Configuration-specific ownership

Maintenance for this exact configuration

These items are filtered to the engine, transmission, trim, and model-year applicability recorded for this configuration. Broad Amazon category searches are suppressed here; shopping links appear only beside catalog-backed part numbers.

Service desk

What this car needs & when

Use this as a service-planning checklist for 1991 Ford Mustang LX 5.0L Convertible 4AT. Start with the interval, confirm which engine or configuration you have, then use an exact ordering reference when one is verified.

Service topics
7
Factory intervals
6
Fitment-scoped
7
Exact references
1

Before orderingIdentify your engine, options and build date.Part numbers and sizes can change within one model year. Shopping links appear only for catalog-backed references; still verify the listing against your vehicle before ordering.

  • Engine oil and filter

    Sourced interval available

    Applies to: 1991 · 2.3L SOHC I4, 5.0L HO V8 · US

    Published interval: 7,500 mi · normal service

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

    Severe service

    Applies to: 1991 · 2.3L SOHC I4, 5.0L HO V8 · US · Ford severe-service operating conditions

    Published interval: 3,000 mi · severe service

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

  • Engine oil filter

    Exact reference available

    Manufacturer application-catalog fitment only; this does not establish an oil-change interval.

    Applies to: 1991 · US

    5.0L High-Output EFI V8

    Baldwin B2

    Applies to: 1991 · 5.0L High-Output EFI V8 · US

    Source: Baldwin Filters — Automotive Applications catalog (2017) · PDF page 260 — Ford 1991, Mustang 5.0L row · checked

    Verified ordering references

  • Engine air-filter element

    Sourced interval available

    Applies to: 1991 · 2.3L SOHC I4, 5.0L HO V8 · US

    Published interval: 30,000 mi

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

  • Engine coolant

    Sourced interval available

    Applies to: 1991 · 2.3L SOHC I4, 5.0L HO V8 · US

    Published interval: 30,000 mi

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

  • Spark plugs (except platinum)

    Sourced interval available

    Applies to: 1991 · 2.3L SOHC I4, 5.0L HO V8 · US

    Published interval: 30,000 mi

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

  • Crankcase ventilation filter

    Sourced interval available

    5.0L HO V8 — PCV valve and crankcase filter

    Applies to: 1991 · 5.0L HO V8 · US

    Published interval: 15,000 mi

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

  • Automatic transmission fluid

    Sourced interval available

    Applies to: 1991 · 2.3L SOHC I4, 5.0L HO V8 · automatic · US · Ford severe-service operating conditions

    Published interval: 30,000 mi · severe service

    Source: Operation CHARM — 1991 Ford Mustang factory service schedule mirror · Normal Service 7,500/15,000/30,000-mile and Severe Service 3,000/30,000-mile records; 2.3L SOHC and 5.0L HO schedules cross-checked · checked

Sources

  1. Ford — 1991 Mustang factory brochure

Other 1991 configurations

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