Spare Tires - Dissimilar Spares

[rdr854]

As you may or may not be aware, it appears that all of the Ford Lightnings are equipped with what is known as a full-size dissimilar spare tire assembly. This means that the tire size is different from the four road tires that are on the ground. Ford also looks at tread design and manufacture for determining whether tires are dissimilar as well.

Because I found out about this sort of issue on my Suburban by accident, I checked the owner‘s manual for the Lightning. The following warnings/instructions/restrictions are excerpted from pages 472-473 of the owner’s manual.

Full-size dissimilar spare
When driving with the full-size dissimilar spare wheel and tire assembly, do not:
• Exceed 70 mph (113 km/h).
• Use more than one dissimilar spare wheel and tire assembly at a time.
• Use snow chains on the end of the vehicle with the dissimilar spare wheel and tire assembly.
• Repair a damaged dissimilar spare tire. Replace a dissimilar spare tire that is damaged.
• Drive extended distances with a dissimilar spare. Tread life is limited to approximately 2,000 mi (3,219 km).
• Use commercial car wash equipment.
When driving with the full-size dissimilar spare wheel and tire assembly, four-wheel drive functionality could be limited.
When driving with the full-size dissimilar spare wheel and tire assembly, it is recommended that you do not:
• Exceed 50 mph (80 km/h) in four-wheel drive.
• Engage four-wheel drive unless the vehicle is stationary.
• Use four-wheel drive on dry pavement.
Using a full-size dissimilar spare wheel and tire assembly can lead to impairment of the following:
• Handling, stability and braking performance.
• Comfort and noise.
• Ground clearance and parking at curbs.
• Winter weather driving capability.
• Wet weather driving capability.
• Four-wheel drive capability.
When driving with the full-size dissimilar spare wheel and tire assembly additional caution should be given to:
• Towing a trailer.
• Driving vehicles equipped with a camper body.
• Driving vehicles with a load on the cargo rack.
Drive cautiously when using a full-size dissimilar spare wheel and tire assembly and seek service as soon as possible.



I have asked my dealer whether a full size matching spare will fit under the truck, and from my read of the manual, I think it should. The dealer is double checking with Ford before they order me a matching wheel and tire.

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[Lightning.Dav]

So, folks who have received your Lariats and Platinums, is it the case that your spare does not match the other tires? And what kind of rim is the spare mounted on?

 

[rdr854]

So, folks who have received your Lariats and Platinums, is it the case that your spare does not match the other tires? And what kind of rim is the spare mounted on?

The spare is mounted on an 18 inch wheel. Regardless of which trim level that you have (Pro, XLT, Lariat or Platinum), the spare is defined as a dissimilar spare since the size is different from the four drive tires on the ground.

My goal is to get a matching wheel and tire so that I do not have that issue. I have posed the question through my dealer, but have yet to get a straight answer from Ford.

 

[RickLightning]

Been that way for decades. Full size spare fits fine on the ICE trucks.

 

[rdr854]

Been that way for decades. Full size spare fits fine on the ICE trucks.

My Suburban was the same way from the factory with a restriction that you could not use 4x4 if the spare was on the front. My solution was to purchase a matching wheel and tire for the spare.

 

[Simpso57]

I want to know if there is any noticeable gain in mileage if you take the spare off. I would put it back on for road trips obviously.

 

[gorwell]

I want to know if there is any noticeable gain in mileage if you take the spare off. I would put it back on for road trips obviously.

No.

 

[Maxx]

When driving with the full-size dissimilar spare wheel and tire assembly, do not:
• Exceed 70 mph (113 km/h).

When driving with the full-size dissimilar spare wheel and tire assembly, it is recommended that you do not:
• Exceed 50 mph (80 km/h) in four-wheel drive.

Unless it has two wheel drive mode, looks like speed limit is 50 mph. Very disappointed.

Any response from your dealer? I would definitely want a matching wheel if I can fit it there.

Anyone knows why spare does not match? Is it cost saving? Weight saving? Ground clearance?…..?

Looks like spare is narrower (265/70R18).

This sticker is from a lariat. I think Pro tires are 275/65R18. I am guessing all spares are the same size regardless of trim.

 

[cvalue13]

I have asked my dealer whether a full size matching spare will fit under the truck, and from my read of the manual, I think it should. The dealer is double checking with Ford before they order me a matching wheel and tire.

many word back on this?

man’s if it is possible, which trim do you have/what did they quote for a matching spare wheel+tire setup?

 

[astricklin]

The lightning technically has two separate two wheel drive systems, not 4 wheel drive, and honestly not even AWD in the way that an AWD system on an ice drivetrain functions.

 

[metroshot]

Unless it has two wheel drive mode, looks like speed limit is 50 mph. Very disappointed.

Any response from your dealer? I would definitely want a matching wheel if I can fit it there.

Anyone knows why spare does not match? Is it cost saving? Weight saving? Ground clearance?…..?

Looks like spare is narrower (265/70R18).

This sticker is from a lariat. I think Pro tires are 275/65R18. I am guessing all spares are the same size regardless of trim.

18" was chosen at the most common denominator for all 4 trims.

And it's for cost savings.

Too expensive to put on the same rims and tire as a spare.

As long as the overall diameter of the tire is the same, that's all that matters for a spare.

When my Lightning needs new tires, I am getting Winter Run Flats for all 4 tires.

That way I get the traction I need year around plus run flat to keep driving with no air in the tires.

Since I don''t change to spares, I will call Auto Club to flat bed it and take me to a tire shop.

 

[RickLightning]

18" was chosen at the most common denominator for all 4 trims.

And it's for cost savings.

Too expensive to put on the same rims and tire as a spare.

As long as the overall diameter of the tire is the same, that's all that matters for a spare.

When my Lightning needs new tires, I am getting Winter Run Flats for all 4 tires.

That way I get the traction I need year around plus run flat to keep driving with no air in the tires.

Since I don''t change to spares, I will call Auto Club to flat bed it and take me to a tire shop.

Make sure you verify that any tires, or wheels, you are considering can support the weight. Haven't stayed on top of the F-150L in that regard, but the Mach-E has extra load tires due to the heavy weight of the car. Can't just throw a Michelin Defender on.

 

[Maxx]

Make sure you verify that any tires, or wheels, you are considering can support the weight. Haven't stayed on top of the F-150L in that regard, but the Mach-E has extra load tires due to the heavy weight of the car. Can't just throw a Michelin Defender on.

I am curious on range hit with grippier tires as well.

 

[metroshot]

Make sure you verify that any tires, or wheels, you are considering can support the weight. Haven't stayed on top of the F-150L in that regard, but the Mach-E has extra load tires due to the heavy weight of the car. Can't just throw a Michelin Defender on.

That's a very good point - never thought about the extra weight this Lightning has to support.

 

[GoodSam]

I am curious on range hit with grippier tires as well.

What would be a grippier tire? I think there is a Motor Trend article about softer, larger, sidewall tires having better efficiency for range https://www.motortrend.com/features/ev-tires-pros-cons-performance-efficiency/. So those with 18" wheels should be showing higher miles/kwh?

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