The downsides of 4WD accessories and modifications

Every now and again I see 4WD’s on the road, or in the bush that really make me wonder what the owner was thinking when they modified it. These days, there are thousands of different modifications you can do to your 4WD. The thing is though, how often have you stopped to consider the downsides?

Yes, there are very obvious downsides, and this comes as part of 15 common mistakes to avoid when modifying your 4WD.

When you see 4WD accessories for sale, they are marketed so you only see how they will benefit your 4WD. Dig a little deeper though, and you will see that every modification you do to your 4WD will have downsides attached to it as well. The purpose of this post is to explore the negative side effects that come from adding 4WD accessories so you can save money and get what you want out of your 4WD.

Ultimately, this is the end goal; to build a 4WD that does what you want it to. Not what others expect it to do, or expect it to look like, but a functional vehicle that is going to fulfil your needs for many years to come.

80 series cruiser
Our mildly modified 80 series

What’s the purpose of 4WD accessories and modifications?

I’d like to think that most people add 4WD accessories to make the vehicle better suit their requirements. Sadly though, this is not always the case. I believe if a 4WD accessory is not making your vehicle more functional, reliable or comfortable then it isn’t worth doing.

Adding a big lift kit for no other reason than to make your vehicle taller is a perfect example of this. Not only is it illegal without engineering, but it has huge downsides, which are often forgotten about.

To improve functionality

These are accessories that make your 4WD easier to use, safer or more capable. Some people don’t want to make their 4WD more capable, and that’s fine; there’s no need to add accessories that don’t improve your vehicle for the way you use it.

Some 4WD accessories that improve its functionality include driving lights, bull bars, UHF radio’s, long range fuel tanks and upgraded suspension. This does not necessarily refer to big lift kits!

Camping with the 4WD's
Set up for easy camping

To improve reliability

At the very least, a 4WD that is not reliable is an inconvenience. However, a lot of 4WD’s travel to extremely remote destinations, and reliability then is worth a lot more. It can be the difference between getting home, or being stranded in the middle of the desert, waiting for someone to come along and offer you help.

There are plenty of modifications and 4WD accessories that improve a vehicles reliability. Aftermarket gauges are the perfect start; boost, oil pressure, exhaust gas temperature, oil temperature and coolant temperature.

After breaking down on the side of the track out of Steep Point and having to wait several hours for help, I know all about what it means to have a reliable 4WD. You can read more here; our 80 series on a tow truck!

EGT Gauge install
A digital EGT gauge

All of these make the driver more aware of the condition at any given time of their 4WD’s engine. This allows them to monitor change, and adjust the way they are driving should anything change to a dangerous level.

Replacing components that are known weaknesses for your model 4WD is a great modification that is going to reduce the chance of failure when out bush. For modern turbo diesels, a Catch can is a smart move especially if you plan on keeping it for many years to come. 

To make your 4WD more comfortable

When you spend hours sitting in your 4WD, there is no reason why you shouldn’t be comfortable. This goes a little further though, as there are plenty of people who live out of the back of their 4WD’s for days on end. Anything that makes your 4WD experience more comfortable is a good thing.

Things like replacement seats, upgraded stereo’s, ports for charging USB devices etc all make your 4WD more comfortable. In many ways, these improve the functionality of your 4WD too.

So what’s the catch with adding accessories?

Every time you add something new to your 4WD, there are downsides attached to it. Some are small and not worth worrying about, but many make more of a difference than you might imagine. However, they all cause one or more of the below:

  • Increased weight and less available space
  • Decreased reliability
  • Not meeting the local vehicle regulations. Is your 4WD legal?
  • Increased centre of gravity
  • Worse fuel economy
  • Worse handling
  • Decreased braking capacity
  • Increased stress on vehicle components

Maybe it’s just me, but I weigh up the pros and cons of every modification on my 4WD before going ahead with it. What benefit does it provide? At what cost does it come? Do I really need it? Is there a better solution?

I want to go through a few of the more controversial modifications people do to their 4WD’s

Wheel spacers and large offset rim disadvantages

There is a reason 4WD’s come out with the rims that they do. They are engineered to handle relatively well, and be reliable for many years to come. By fitting wheels with a larger offset or installing wheel spacers, the wheels stick out more, and give your vehicle a wider stance. That’s great, right? The problem though, is that it puts additional stress on the wheel bearings and various other components.

In Australia, wheel spacers are illegal on road, so don’t use them. Many 4WD’s have changed to slightly different offset rims, but be aware that the wider you make the stance, the more likely you are to wear out wheel bearings and break components.

GQ with a wide wheel track
A dedicated off road vehicle with a wide stance

The downsides of big lift kits

There are a lot of 4WD’s driving around with big lift kits. Asides from the fact that very few are engineered, unless the lift is done properly with all of the components required, your vehicle will not handle as well as it did without the lift kit.

Perhaps an even more serious consideration is the higher centre of gravity. The chance of you rolling your 4WD go up considerably when lifting a 4WD. I’m not saying lift kits are a bad idea; they are a requirement when fitting bigger tyres, but you want to limit the height of the vehicle as much as possible, and at the very least, ensure that you don’t reduce the vehicles safety factor.

Lift kits are the most common way to make a 4WD illegal. In WA, your 4WD is only allowed to go up 50mm, and this is the total of all increases caused by tyres, body lifts and suspension lifts. If you go over that without engineering, your vehicle is illegal.

The only thing that actually increases your ground clearance is fitting larger tyres, so only lift your 4WD enough to fit the tyres you are running. Remember to stay within the local regulations too, or get your 4WD engineered. A perfect example of this is an 80 series. You can run 285/75/R16s (50mm bigger in diameter than factory) without a lift kit, but many people choose to run them with 2, 3, 4 and even 5 inch lifts. Is it really necessary?

This is one of 32 ways to make your 4WD illegal, and it’d be worth avoiding them!

4WD lift kit negatives
A huge lift kit

Bigger tyre disadvantages

A very common modification is to fit larger tyres to your 4WD. One or two sizes is common, but many people go much further than this. Bigger tyres are the only way to truly give your 4WD a greater clearance, but they come at a number of fairly large costs.

Lifted 80 series
Big rubber on an 80 series

The moment you jump into your 4WD after fitting bigger tyres, you will notice the following:

As soon as you put your foot down on the accelerator, you will notice a loss of power. It might not be much, or it could be quite a lot, depending on the tyre size you’ve changed to, and the engine you are running.

Your speedometer, trip meter and odometer will not read accurately any more. They will be out by the percentage of diameter change in tyres. For many vehicles, going up one tyre size means that your gauges are out by 10%. When you are doing 90km/h you are really doing 99km/h and this is not ideal. This really means you should factor servicing off your odometer minus the percentage it is out. When you work out your fuel economy, make sure you consider the difference too.

The next thing you notice is your braking capacity is reduced. Given that they are probably the most important safety device fitted to a vehicle, this is a very serious implication!

Over, time, you will notice the following as well:

Bigger tyres put more stress on your driveline. You are much more likely to break a CV, bust a diff or damage your steering components because each part of your 4WD has to work harder to operate the tyres.

Your fuel economy is going to get worse. Bigger tyres on a 4WD make the engine work harder (even if it’s at a lower RPM) and thus consume more fuel.

The police pull you over more often because your vehicle may or may not be road legal. If it isn’t, any they give you a sticker, you can be in for a world of pain trying to get it off! An illegal 4WD opens up a world of potential risk if you are involved in an accident; have a read of the post I wrote on 4WD Insurance.

Huge rubber on a 105 series
37 x 16.5 inch tyres on a 105 series

4WD accessories often snowball once you start. For example, one might fit larger tyres, only to find that they scrub when being flexed up, so then they purchase a lift kit. From there, they find they don’t have enough power to turn the bigger tyres, so they do engine modifications (chip, exhaust, turbo upgrade etc).

With the additional power and extra stresses on the driveline, they start snapping CV’s, so these are removed and upgraded to chromoly. This process can go on and on forever, and believe me, it does!

Adding more weight than you are allowed

I’d say that most 4WD’s travelling for more than a week at a time would be over loaded. If you sit down and add up the weight of everything on board, I bet you would be surprised at the final figure. You can read more about this on the post I wrote a few weeks ago – What does your 4WD weigh?

Essentially though, the more your vehicle weighs, the less quality handling it will have, the worse your economy is going to be, the more stress you put on the car and the more fuel you are going to use. Pick your accessories wisely, or they will cost you a lot. Remember if you are over the GVM you are at serious risk from an insurance perspective too.

My bogged 80 series
The lighter the 4WD the better!

Excessive engine modifications

You can never have enough power, right? Maybe it’s just a bloke thing, but we seem to be forever trying to get more out of our engines than what they originally came out with. There are numerous ways you can go about getting more power; upgrading the exhaust, turbo, air intakes, installing a chip, intercooler, supercharger and the list just goes on and on.

Broken Patrol at Mundaring
This is not what you want in the middle of no-where!

Some of these modifications provide numerous benefits without coming at much of a cost, but you want to at least consider any potential problems that they could cause. Improving the air flow, installing a non-restricting exhaust and adding an intercooler are all proven ways to make your 4WD more reliable whilst improving the economy and getting more power.

However, there are many engine modifications which will not make it last longer. If you are getting more than 30% increase in power, is it going to be beneficial to the engine? Obviously, there are exceptions to the rule, and many modifications have proven to provide extra power whilst reducing fuel consumption and still maintaining the level of reliability that we all want from our 4WD’s. All I’m suggesting is that you pay attention to reliability first and foremost!

Storing too much weight on the roof

After seeing a good mate of mine roll his Patrol on a gravel road, I’ve been very aware of putting too much weight on my roof. Most 4WD’s are only rated to take 100kg on the roof anyway, and if you have a full length steel roof rack, you are going to have used up a sizeable chunk of that 100kg without adding anything on top. 

I see people regularly with big storage boxes on the roof, LPG bottles and more Jerry cans than you would want to add up. Asides from the risk of damaging your roof, your centre of gravity is ridiculously increased, to a level where it would be very easy to tip your car over. Keep the weight down as low as possible, and use the roof racks for light weight, bulky items (chairs, swags, tents, fishing rods etc). Check this out for more information: Roof Rack weight limit.

Final words

If this post seems a little negative, I apologise. I’m not trying to be negative. 4WD accessories have transformed the way 4WD’s perform, and have made my 80 much more enjoyable to travel with. However, I think it’s a good idea for those modifying their 4WD’s to consider any potential downsides, so they aren’t bitten down the track. I don’t have a problem with those running big tyres and lift kits.

Yeagarup on the beach
Get out there and enjoy this amazing country in your 4WD’s!

If this is what you need to suit your requirements, then that’s fantastic. Anything you do to your 4WD should help to achieve what you want out of the vehicle. At the end of the day though, what is most important is that you complete your 4WD trip without any major drama’s along the way!

What about you; how do you go about choosing 4WD accessories? Do you regret buying something down the track? What have you learnt when modifying your 4WD?

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  1. Hey mate,

    Cheers, and yep, easy to copy others or fit accessories without really thinking it through!

    Learning from others mistakes certainly saves a lot of time, money and heartache!

    Take it easy

  2. Guesty’s Adventures says:

    Nice practical article Aaron!

    It seems people are quick to just go buy the biggest and ‘best’ accessories for their vehicle but forget about the consequences of these changes.

    I think a lot of people would benefit from critical research into accessories, and even reaching out for assistance to 4WD Clubs and Forums (albeit in moderation) as there is a lot of good information scattered between different organisations.


  3. Excellent articles. Thankyou.

  4. Hey Damian,

    Your phrase isn’t wrong! Nice with with the 130 – I like them.

    Offset wheels are OK, but you do have to be cautious with them, or be prepared to do more maintenance.

    All the best

  5. Hi Aaron,

    Great article. I’ll quote a phrase I once read, “Perfection is achieved when there is nothing else left to remove”
    Having had an Subaru Impreza WRX and buying into the marketing hype of “Performance” products I soon learnt the hard and expensive way of what that term meant. I now own a Land Rover Defender 130 and I am again learning the perils that you speak of in your article.
    I found the article after searching for offset and if it puts more stress on components. In my mind it acts as a leaver and leavers long enough are able to achieve some serious forces. So I’ve got my answer and thank you.

  6. Hey Kris,

    I’m glad it was useful. All the best with your modifying!


  7. HI Aaron
    This is an honest eyeopener. Great article. Im planning on doing some mods, but after reading your article, I have started to think what is worth and what is not. Good job and thanks mate

  8. Laurence McCarthy says:

    This is an honest and very practical review Arron well done !

  9. Hey Chuck,

    It’s certainly an interesting one, isn’t it?!


  10. Chuck Davis says:

    Good morning Aaron,
    I found your post to be honest and not negative at all. I’m a certified four-wheel drive instructor in the United States. I discuss this issue with mostly civilian clients, it’s usually not what they want to hear.