4x2 SUV’s - what’s their purpose?

[Cyclone101]

Thank goodness for MAP and MAF sensors.

But, in the interest of accuracy I will address some things.

Carburettors are not all created equal. Some carburettors can compensate for air pressure, they would need a slide diaphragm assembly to do so.

Many carbs, even the beloved DCOE45 Webbers, do not compensate internally and as such Webber themselves recommends re-jetting for optimal performance above 4000ft.

Now, you don't have to, it will run just fine, but if you want the perfect AFR you would need to compensate for Density Altitude (DA)

Now, how this is relevant do mock-SUVs, I don't know.

[jelo]

And it is true, that a conventional carburetor tuned to run at the right mixture at sea level would cause the engine to run lean at higher elevation / altitude. It is not necessarily all that noticeable if the difference in altitude is a few hundred meters, but it certainly is noticeable between seal level and e.g. Windhoek or Johannesburg elevation. Carburetors for piston aircraft engines have a mixture control lever which one adjusts when climbing or descending.
It was therefore a good idea to have the car's carburetor adjusted if one would stay at a different elevation for a longer period of time in order to avoid running the engine too lean or too rich.

Thank you, finally somebody that understands.

[XJ Junky]

I still think bakkie based 4x2 SUVs are silly

[Francois Theron]

And it is true, that a conventional carburetor tuned to run at the right mixture at sea level would cause the engine to run lean at higher elevation / altitude..

Are you sure about this?

[Fluffy]

Are you sure about this?

Yep, your suspicion is correct, other way around.

[HugoNotte]

Are you sure about this?

Thanks Francois, you are right. A carburetor adjusted for sea level would cause the engine to run rich at higher elevations.

[dirtshark]

I still think bakkie based 4x2 SUVs are silly

Lol, still at it ......I will take you on a dirt road that will change your perception pronto

[hunter26]

I'm just glad my old 4x2 subsonic diesel bakkie has a std jet fitted to it.

[MariusFourie]

With the rain we've had, a 4x2 struggles to get up my driveway.

[XJ Junky]

Lol, still at it ......I will take you on a dirt road that will change your perception pronto

As long as it’s not in a Fortuna. Like is too precious

[Rainier Vermaak]

As long as it’s not in a Fortuna. Like is too precious

But Fortuners are the second best, just after the non-existent Amarok based SUV.

[Schambies]

Someone mentioned earlier in the thread that upfront costs might deter a buyer from choosing the 4x4 model over the 4x2. Now, I can understand that being the case when buying second hand and having a limited budget, but I think it's a little strange that 600k on a new vehicle is OK, but adding 40k for the 4x4 kit is too much. Especially because down the line the 4x4 vehicle can be sold off for slightly more. Everyone is free to choose what they want, but saving less than 10% on a vehicle to forego a huge feature makes no sense to Me, maybe it does to others.

Also, yes, the majority of Tuna and Everest owners have never seen anything but tar, but on the odd occasion that they hit gravel having 4x4 might be the difference between having an accident or not

[HugoNotte]

Someone mentioned earlier in the thread that upfront costs might deter a buyer from choosing the 4x4 model over the 4x2. Now, I can understand that being the case when buying second hand and having a limited budget, but I think it's a little strange that 600k on a new vehicle is OK, but adding 40k for the 4x4 kit is too much. Especially because down the line the 4x4 vehicle can be sold off for slightly more. Everyone is free to choose what they want, but saving less than 10% on a vehicle to forego a huge feature makes no sense to Me, maybe it does to others.

Also, yes, the majority of Tuna and Everest owners have never seen anything but tar, but on the odd occasion that they hit gravel having 4x4 might be the difference between having an accident or not

I hear you. But those 40k might be part of the downpayment for the Polo.
Those of us who grew up BC, might still remember that even well off farmers who had several bakkies and other vehicles on the farm, often had only 1 4x4, the others were 4x2.
People were happy to take their platkarre on gravel roads, because many of today's tar roads were not tar roads yet.
Now 4x4 has all of a sudden become an essential feature for many.
It might also have become more affordable in relative terms.

[Hooly]

Someone mentioned earlier in the thread that upfront costs might deter a buyer from choosing the 4x4 model over the 4x2. Now, I can understand that being the case when buying second hand and having a limited budget, but I think it's a little strange that 600k on a new vehicle is OK, but adding 40k for the 4x4 kit is too much. Especially because down the line the 4x4 vehicle can be sold off for slightly more. Everyone is free to choose what they want, but saving less than 10% on a vehicle to forego a huge feature makes no sense to Me, maybe it does to others.

Also, yes, the majority of Tuna and Everest owners have never seen anything but tar, but on the odd occasion that they hit gravel having 4x4 might be the difference between having an accident or not

The problem is that with a lot of the makes you cannot simply have the base model with only 4x4 as the extra. Most of the time it means you have to go up to a much higher specced model plus the 4x4, then the price difference becomes substantial.

You can buy a Ford Everest XLS for around R550k if you want a 4x4 from any of the vehicles of the same type including Ford, there is about a R100k price difference!

[Schambies]

The problem is that with a lot of the makes you cannot simply have the base model with only 4x4 as the extra. Most of the time it means you have to go up to a much higher specced model plus the 4x4, then the price difference becomes substantial.

You can buy a Ford Everest XLS for around R550k if you want a 4x4 from any of the vehicles of the same type including Ford, there is about a R100k price difference!

Yes you are right - I guess my argument was focused on people buying expensive top of the line trims and not specc'ing the 4x4 in. Bakkies are a whole different story. I can see a scenario where a decent bakkie doing work on a farm might not need 4x4. The dude might just want some feature comforts while pulling a trailer.

[Paul#25]

NOT TRUE.....

At worst, you had to alter the ignition timing but not jets.

Normally this different timing for different altitudes, ultimately was not because of performance, but rather because of hard starting and because of pinking (pre-ignition). Just changing your fuel grade between 93 and 98 octane achieved similar results.

In the 70s and my folks lived in Margate, I lived in Joburg. I used to go down to Margate once a month and to get the best performance a slight advancement or retardation of the ignition timing was all that was required.

At the time I drove Alfas (owned many of them) and Weber or Dellorto side draught carbs have about 8 fuel and air jets, so 16 jets on twin side draughts.

To have to change jets would not have been practical and totally impossible for most people.

Not entirely true.
Changing jetting for different altitudes was always done with performance motors using carbs. When I raced bike's in the 80's we changed jetting between the Rand Airport track in Germiston and Zwartkops in Pretoria. With some of the 2 strokes like the TZ250 and 125 you rejetted if the barometric pressure changed.
With my Lotus 7 replica I ran 45mm Webber carbs on a very highly tuned Toyota 1600 cc engine. If I didn't rejet for coastal races I'd have destroyed the motor by the second lap of practice.
With normal road cars the band of acceptable performance and tuning is lot wider. The adjustment of the ignition timing was to prevent detonation or "knock".
On modern cars all the little adjustments are done by the ECU that senses atmospheric conditions, temperature and fuel volatility. The knock sensor on the block will change the ignition timing as it senses the start of a knock.