Is 8×170 the same as 8×6.5, and will 8×170 fit 8×6.5?

Is 8×170 the same as 8×6.5, and will 8×170 fit 8×6.5?

Wheel fitment is often one of the more confusing aspects of working on vehicles. With various patterns in use both metric and imperial, it can be easy for the average motorist to get lost in the specifications. A common source of puzzlement revolves around two popular patterns – 8×170 and 8×6.5. Our roads are filled with cars employing one or the other, yet their relationship remains ambiguous for many. In this in-depth explanation, we aim to unravel any confusion by setting out clearly whether these patterns are indeed interchangeable.

To begin, it is helpful to provide some context on wheel bolt patterns in general. All roadgoing vehicles utilize a pattern of bolts or studs to securely fasten wheels. The specification consists of two numbers – the first refers to the number of bolts or studs, while the second is the diameter or pitch between them in millimeters. The most prevalent configuration internationally is now 5×120, although older cars from the 1950s-70s often used a 5×4.5 inch imperial standard. Larger commercial vehicles may employ variations like 6×145 or 8×185.

Is 8×170 the same as 8×6.5, and will 8×170 fit 8×6.5?

Patterns are determined by the wheel hub design to provide a straightforward, repeatable method of attachment. However, with the industry slow to adopt globally synced standards, confusion can arise when multiple legacy sizings co-exist. 8×170 and 8×6.5 are a prime example, so let us now delve into their precise definitions and critically evaluate whether they refer to the same fitment.

8×170 is distinctly different to 8×6.5

The first point to acknowledge is that 8×170 and 8×6.5 are decidedly not equivalent specifications. 8×170 denotes a bolt circle with 8 bolts spaced 170mm apart from center to center. This is a pure metric classification employing millimeters exclusively. Meanwhile, 8×6.5 indicates 8 bolts on a 6.5-inch (165.1mm) bolt circle when converted from imperial measurements.

On the face of it, 6.5 inches and 170mm would seem to be measuring much the same physical distance. However, we must remember that imperial units do not perfectly align with their metric counterparts. 165.1mm is 4.9mm narrower than a true 170mm bolt circle. While this may seem a small margin, it is significant enough that these patterns are tailored for physically unmatched hub designs.

Interchanging 8×170 and 8×6.5 wheels without modification would lead to clearance and stability issues. The bolts may not center or fully engage the hub threading. This poses a serious risk of wheels working loose over time with dangerous consequences. Those who have made this mistake often describe vibrations and pulling under braking. Therefore, we can definitively state that 8×170 and 8×6.5 are distinct specifications that should not be viewed as directly substitutable.

But can an 8×6.5 fit an 8×170 hub with adapters?

Now that we have dispelled any equivalence between the patterns, a logical follow-up question emerges – is there any way to fit an 8×6.5 wheel onto an 8×170 hub, or vice versa? Here the answer is more nuanced. While the bolt circles are non-conforming in their natural forms, adapters provide an option to bridge the gap.

Wheel spacers, also sometimes called bolt pattern or hub mount adapters, are effective sleeves that sit between the wheel and hub. They contain bolts matching the hub pattern on one end and the wheel pattern on the other, separated by a precisely machined flange. When installed, they preserve the overall bolt circle diameter and threading to enable a secure union.

Adapters are available commercially for many common mismatch scenarios like fitting 5×114.3 wheels to a 5×100 hub. And models do exist to join an 8×170 hub to 8×6.5 wheels or the other way around. With the right adapter of the correct thickness (4.9mm in this case), the physical clearance is regained to turn an otherwise impossible join into a feasible workaround.

But are wheel adapters always a safe solution?

While adapters provide an option to unite discordant bolt patterns, their usage does introduce some potential downsides worth flagging. The main risks surround the additional flex they introduce into the overall wheel structure. Adapters act as a coupling joining two independent circles, with imperfect stress transfer compared to a single integrated ring.

Under hard cornering, braking, or acceleration, this extra compliance can translate wheel vibrations to the suspension or steering linkage. Over the long haul, it may also accelerate wear at the adapter interfaces. There have been isolated but tragic incidents of clamp joints coming loose at speed. Most automotive experts therefore caution against relying on adapters for primary on-road use cases.

That said, lightweight spacers are generally acceptable for occasional track days or exhibitions where reduced loadings apply. Larger commercial types facilitate equipment interchanges where no prudent alternative exists. But for daily drivers, it is preferable to directly match bolt patterns where possible through hubs, wheels, or complete hub/knuckle replacement. The small impositions of mismatched designs pale compared to the potential consequences of adapter fatigue.

While 8×170 and 8×6.5 appear numerically close, they describe physically unmatched wheel bolt patterns separated by 4.9mm. These specifications should never be considered interchangeable without modification to avoid safety risks.

Wheel bolt pattern adapters provide one solution for joining non-native patterns like 8×170 to 8×6.5 wheels. However, their use introduces flex that accelerates wear over the long term and, in rare cases, can lead to detachment at speed.

NTI Nut & Bolt Set NUT BOLT WASHER, (3/8 x 4Inch, 100mm length),  Zinc-Coated (10 Pcs set) Price in India - Buy NTI Nut & Bolt Set NUT BOLT  WASHER, (3/8 x

For on-road use, directly matching bolt circles through dedicated components is preferable from a safety perspective. But adapters remain practical solutions for track, show, or heavy equipment applications where reduced loading applies and safety consequences are minimized. With this comprehensive explanation, we hope to have eliminated confusion around two similar-sounding, yet importantly different, wheel specifications.

Differences between the 8×6.5 and 8×170 wheel bolt patterns:

Making Sense of Bolt Patterns

When fitting new wheels, getting the bolt pattern right is crucial. But with measurements in both Imperial and metric, patterns can be confusing. Two common sizes are 8×6.5 and 8×170 – but what’s the difference?

8×6.5 vs 8×170: The Size Difference

8×6.5 refers to 8 bolts spaced 6.5 inches (165.1mm) apart. 8×170 has 8 bolts 170mm apart.
The key difference is 4.9mm – 8×6.5 is almost 5mm narrower than 8×170.

Typical Vehicles

8×6.5 is predominantly a US standard, found on many classic and muscle cars from the 60s and 70s.
8×170 is a modern metric pattern, often used on European and Japanese performance vehicles.

Will an 8×170 Fit an 8×6.5 Hub?

With wheel adapters, yes. Adapters make up the 4.9mm gap, but protruding studs may need trimming for a proper fit.
Adapters introduce some flex, so matching patterns directly is ideal where possible.

Will an 8×6.5 Wheel Fit an 8×170 Hub?

Also yes, but wheel adapters are required to bridge the width difference. As with 8×170 wheels, stud trimming may be needed in some cases. Adapters aren’t ideal for daily use due to added vibration and wear over time.

By understanding the measurable size difference between 8×6.5 and 8×170, it’s clear they aren’t interchangeable without modification. With the right adapters, either pattern can fit the other where needed.

Common types of wheel adapters:

Making the Right Connection: Types of Wheel Adapters

Wheel adapters come in various widths to bridge different bolt pattern sizes. Here’s an overview of typical adapter options:

1 Inch Adapter

Primarily used for smaller mismatch cases of 5-10mm. Offers a secure fit for occasional track use. Easy to install.

1.5 Inch Adapter

Covers pattern differences up to 15mm. Converts common sizes like 5×114.3 to 5×100. Usable for regular driving when no alternative exists.

2 Inch Adapter

Matches disparities up to 20mm. Connects less common patterns where 1.5″ won’t suffice. Still street-able if the wheels/hubs can’t be changed.

3 Inch Adapter

Bridges have enormous 25-30mm gaps. Intended for industrial or show use only where safety isn’t critical.

Risks of 3 Inch Adapters

Amazon.com: EZAccessory 2 Billet Wheel Adapters 5x5.5 to 5x135 (5x139.7 to  5x135) Thickness 1 Inch : Automotive

Add excess flex. Significantly increase the chance of vibrations loosening clamp bolts over time. Not rated/tested for sustained high-speed use. Dangerous to rely on for typical roadway driving. Best limited to stationary applications.

While wider adapters allow more pattern pairs to mate, each additional width brings proportionally greater risks. For reliable road use, narrower options like 1-1.5” are generally the safety limit before considering a hub/knuckle swap.

Think Twice Before Using Wheel Adapters

Adapters seem convenient for mismatched bolt patterns, but regular use brings risks. Consider alternative options whenever feasible.

FAQ: What bolt pattern is 8×170?

8×170 refers to 8 bolts spaced 170mm apart in a metric bolt circle. Common on European and Asian performance vehicles.

FAQ: Details on 8×170 bolt pattern

8×170 is a modern metric standard. Fits hub designs made for its exact 170mm width.

FAQ: What bolt pattern fits 8×6.5?

8×6.5 (8 lugs 165.1mm) is commonly found on classic American muscle cars from the 60s-70s.

FAQ: Details on 8×6.5 bolt pattern

8×6.5 indicates 8 bolts on a 6.5″ or 165.1mm bolt circle when converted from Imperial. About 5mm narrower than 8×170.

FAQ: Can the bolt pattern be changed?

Yes, the bolt pattern can be changed by replacing the hub/spindle assembly with one featuring a different pattern.

FAQ: Methods for changing bolt pattern

Common ways are hub/knuckle swaps or retrofitting a hub designed for a desired pattern like 8×170.

FAQ: What is the Silverado Bolt Pattern?

Most 1999-2013 Silverados use a 5×4.5″ or 5×114.3mm bolt pattern.

Final thoughts – While 1″ adapters can work for track days, any adapter adds flex and vibration over time. Whenever possible, match patterns directly through hub/knuckle replacements for the safest street use.

Closing remarks – We advise considering native pattern replacements before resorting to adapters long-term. 1″ may be safest, but still introduces more risk than a direct hub/knuckle fit. Your safety isn’t worth the gamble – change the pattern properly if needed.