BF Goodrich ATK02 Fuel Consumption

I put k02s on my 04, I can't say for sure as they're a larger size, but I don't think it's had a huge effect on fuel. They replaced a worn set of knock off  k01s (standard size), and I found them to make it slightly slower to 60, and wander more in corners, probably with the extra tread, but off road they're fantastic.

I made the purchase and fitted the BF Goodrich AT KO2 215/75/15 to my Gen4 LCV and it does look great. Did a bit of off roading and they are certainly more capable then the Dulers that were supplied with the van.

I've done about 300 miles in it this week and normally on that work trip away for 5 days I always get somewhere in the 38mpg bracket, but was somewhat disappointed to only get 33.4mpg this week which is more of a drop than I had expected. I've had my tyre pressures set to the recommended 26psi for light loads so have now upped them to 30psi around to see what difference that makes.

I was wondering what other people are setting there tyre pressures to with the same setup? And if you're sticking to the Suzuki recommend tyre pressures for the standard tyres?

Performance has also taken a knock I've got to test it exactly on the same piece of road but from an early test I think the top speed is down by the best part of 10mph (obvs I tried this on the Autobahn) and performance through the gears is also noticeably reduced.

The vehicle feels more taught when cornering in.the dry with good traction when pressing on, but in the wet depending on the tarmac they really aren't great. Maybe a few more miles to take the top layer off them may help with this.

Remember that any change in tyre size affects both the odometer (distance you travel) and the speedometer (speed you drive). Even a small increase of 2% will see you recording 2% fewer miles whilst driving 2% quicker, the cumulative affect being a higher perceived fuel consumption when it may not have changed at all.
The only accurate way to measure is tank-to-tank, adjusting the mileage for the change in tyre size. I'd be surprised if you saw any change.

A drop from 38 ish to 33.4 is 12%. Differences in tyre dia. are present but even so 12% begs the question in big letters WHY. Is this an error in the maths or a problem with filling up the tank? Yes, do it all again to eliminate problem areas and use a different fuel pump at the station. Your original figure of 38 is a bit low but probably due to how you need to drive and where you do your driving. You must, obviously, do your best to duplicate everything that was the normal routine.
We await the new results with baited breath!

Roger

wrote:

I made the purchase and fitted the BF Goodrich AT KO2 215/75/15 to my Gen4 LCV and it does look great. Did a bit of off roading and they are certainly more capable then the Dulers that were supplied with the van.

I've done about 300 miles in it this week and normally on that work trip away for 5 days I always get somewhere in the 38mpg bracket, but was somewhat disappointed to only get 33.4mpg this week which is more of a drop than I had expected. I've had my tyre pressures set to the recommended 26psi for light loads so have now upped them to 30psi around to see what difference that makes.

I was wondering what other people are setting there tyre pressures to with the same setup? And if you're sticking to the Suzuki recommend tyre pressures for the standard tyres?

Performance has also taken a knock I've got to test it exactly on the same piece of road but from an early test I think the top speed is down by the best part of 10mph (obvs I tried this on the Autobahn) and performance through the gears is also noticeably reduced.

The vehicle feels more taught when cornering in.the dry with good traction when pressing on, but in the wet depending on the tarmac they really aren't great. Maybe a few more miles to take the top layer off them may help with this.

I noticed the performance impact when I fitted 215/75R15 AT's (Maxxis Wormdrive). It was less peppy on acceleration. Can't say I really notice much difference in top speed though.

MPG wise, running about locally I get 32-34mpg. Although a long run the other week returned 38.6mpg, but it was cross country and driving gently. Motorway driving (anything over 3000rpm) IMO makes it drink fuel. A long motorway stint at 70mph on cruise control will see low 30s.

If you had 195/80R15 on your LCV and went to 215/75/R15 that is only 1.5% bigger, so your speedo would under read by 1.5%, no where near enough to make any meaniingful difference.

However, they 215/75/R15 tyre will probably weigh a fair bit more and it is likely that it is the extra weight increases the inertia and leads to higher fuel consumption.

Also the rolling resistance of the KO2 is probably much higher than the Dueler (road tread) tyre.

12% sounds a lot, I didn't notice as much difference going from 205/70 road/AT to 215/75 Maxxis on my Gen3, then the speedo was further out than your move.

Robin