Fuel Consumption after new tyres???

[NISMOnator]

Hello Almal,

Ons Patrollie aka Grizzly leef nou sy naam volheid uit op alle gebiede. Veral op die dors gedeelte!!!

In short, use to have the stock Bridgestones on HT 265/65/17
On a trip down to CPT we got about 6 - 6.5 km on a litre which wasnt bad as the vehicle was really laden and heavy roof rack with lots on it.

Then after trip I realized that the old tyres is in bad shape and needed replacement. I opted as all on forum or most says the 285/70R17 is the best to go for when doing offroading. Ok and this is where everything changed!!!
Fuel consumption went through the roof! Looking at 3.5 - 4.5 km per litre. Note that in town driving we use to get around 5.5 km per litre.

Now it has just become scary. The wife is complaining everyday more and more.

Is this normal with the new tyres?

Thank you

[David]

Your 285 tyres have a greater circumference than the 265's. Now your speedo is nearly 100% accurate but your trip meter shows less km's than actual. Compare the distance with a GPS and work out the % error

[NISMOnator]

Thank you David,

I will do the comparison and try and work it out. I am aware that the speedo is 100% accurate. 80 is 80 and the wife still doesn't get it! Traffic fines.....

[Herrie]

Toe ek die 265/75R16 verander het na 285/75R16 toe is daar net 3km/h laer as 100km/h en die afstand is 4% minder as normaal afstand.

[Clem]

What tread pattern are your new tyres?

[Peter Connan]

Your new tires are probably 10-12% larger than the old ones in circumference, and you need to add that to the distance travelled for accurate calculations.

However the difference in your case sounds like much more than that.

Opinions vary on how tires affect fuel consumption. I have found my car to be pretty sensitive to uphills and wind direction, but not to tire size or tread pattern.

Are you sure it's only the tires? Could be driving style, type of trips or a management problem too (such as a dirty MAF)...

[NISMOnator]

It is A/T tires.

See pictures for tread pattern.

[Clem]

Not surprised your fuel consumption went up if you went from HT tyres to AT tyres. That alone will account for about a 15% difference in consumption.

[dieselfan]

I was watching a US overlanding channel, when going the same jump as you did their LC shot up too, they fitted a better diff ratio putting revs UP and said they were getting better than stock consumption wise. Something I'm considering.

[Chris Skinner]

When I went from standard road type tyres (michelin) on the 4.8 to the big BFG muds, I noticed no degradation in my fuel cosumption - you need to do your sums properly to compare as the circumference is roughly 10% larger so the the distance travelled is 10% more - never mind what the trip meter reads. Most people dont take this into account in their calculations, and yes, it looks daunting to the uninformed...