Fuel economy & noise on A/T tyres

Submitted: Monday, Feb 26, 2007 at 15:01
ThreadID: 42715 Views:5036 Replies:10 FollowUps:3
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After checking many threads which deal with performance, tyre life and reliability, I can't seem to find any user feedback on fuel economy and noise, when anyone has changed tyre brands, so here's my question:

I have a 90 series Prado T.D It's running its third set of Dunlop GrandTreks fitted in 2003. I brought this vehicle second hand. The tyres have now done approx 45,000 Kms and I'll get another 10,000 Kms out of them no problem. As its my company car I run a tight log book. Its 3 year average fuel usage is 11.5 litres per 100 Km. On country runs it gets down to 10.5 litres per 100 Kms but I've never been able to better that mark. (the car is an auto)

I like the look of the new Cooper ATR rated as a 70-30 tyre. As I plan to do a little more off-roading, a bit more dirt and mud capability would be welcome.

The question is economy and road noise. Has anyone out there changed their GrandTrek's for Cooper ATR's and recorded a difference in fuel usage (up or down). As for noise, well, your impression on any changes their either.

As a side issue, does anyone know if the Cooper's are a larger diameter than the GrandTrek's and therefore whether clearance under the wheel arch is affected.
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Reply By: Patrol_Driver - Monday, Feb 26, 2007 at 16:01

Monday, Feb 26, 2007 at 16:01
I had the Cooper ATRs (passenger construction) on my Patrol and I would never get them again. They lost tread blocks like they were made of chewing gum, I also punctured on and shredded another (both on the rear) on my outback trip.

Before anyone tells me that I should have bought the LT version, the passenger construction was recommended to me by the "specialist" cooper dealership.

I wrote to the Australian Cooper distributor and they kindly agreed to refund me the balance of the tyre warrantly in cash.
AnswerID: 224075

Reply By: Member - Des - Monday, Feb 26, 2007 at 17:42

Monday, Feb 26, 2007 at 17:42
The Grandtreks will be 265/70R16 in passenger construction. The Cooper ATR is available in the same size, also in passenger construction. There are quite a few other AT tyres available in that size too, but very few in LT construction (BFG is one, I think). The next size up, 265/75R16, is far more common in LT.

The diameter should theoretically be the same between different brands in the same size, but is rarely identical. Only way to check precisely is to run a tape measure around one.

As for fuel consumption, I can only comment on going from Bridgestone D693 to Pirelli Scorpion ATR in petrol Prado 90, both in 265/70R16. I monitor fuel consumption closely and can't detect any change, for better or worse. I find that the biggest variable for fuel is in tyre pressures - even going from say 34 to 38 psi for hwy travel saves about 2L/100km. Maybe experiment a bit with pressures if you want to improve fuel economy.

As for noise, the Pirellis are excellent. Mate has Bridgestone D694s and finds them very quiet too. I imagine the Cooper ATRs would be similar, because they are in the same class, but have no personal experience. I am told that more aggressive treads (e.g. BFG, Cooper ST, Dick Cepek, etc) are significantly noisier. I think it is fair to say too that stopping distance on bitumen is longer with more aggressive treads. (Tests by Austn 4WD Monthly last year tended to confirm this.) That is the trade-off for more grip off-road.

Good luck,
AnswerID: 224108

Reply By: V8Diesel - Monday, Feb 26, 2007 at 18:26

Monday, Feb 26, 2007 at 18:26
I had Cooper ATR's in 305/70/16 on my Cruiser. They seemed very good although I did chew them up a bit. One thing that did become apparent was their gravel holding ability. When returning to the bitumen they fire stones into your guards for a while. Another poster made reference to this recently.

Apart from that they were nice and quiet. I had a set of Cooper ST's for a while but got rid of them after a few hundred km's due to noise.

Can't give a long term review as my Cruiser was written off (not because of tyres I should add!)
AnswerID: 224120

Reply By: Muddy doe (SA) - Monday, Feb 26, 2007 at 18:34

Monday, Feb 26, 2007 at 18:34

Made the change to Cooper ATR on my 120 series Prado and they seem excellent as an allrounder tyre for mostly onroad with some offroad. No real difference in fuel economy - seem very quiet compared to my other set that are Goodyear MTR's (which also jack up fuel consumption by about 1l/100km). I run the ATR's for long distance blacktop runs but they handle occasional offroad work really well. The Goodyear MTRs are awesome offroad but I doubt you would appreciate the noise on the road!

My ATR's are the LT construction and while there are a few small chips here and there I would not say it has been a major issue given the stony roads I have taken them over. They are LT270/70R17 so are a bit bigger than you would put on the 90 series but if you get the LT construction you should be pretty happy.


AnswerID: 224124

Reply By: Member - Norm C (QLD) - Monday, Feb 26, 2007 at 20:32

Monday, Feb 26, 2007 at 20:32
I had Cooper ATRs on my Hilux for the first 20,000 KM. I found them to be an excellent on road tyre, with very little road noise, excellent grip and good on wet bitumen. Off road they were quite adequate, but not great in mud or wet roads (not bitumen). I wrecked a side wall on one while off roading, but that can hapen with any tyre.

They clog up with mud pretty easily and don't self clean until you pick up some speed.

I changed over to Cooper STs before our Kimberley trip last year. I wanted to standardise between Hilux and CT and also 3 spares, so I was up for a number of new tyres anyway. Took the opportunity to get a more aggressive tyre with better off bitumen capability.

By comparrison, the STs are much noisier on road (but OK for us). STs are a much better off road tyre and self clean quite well. Can't give a comparsion to the Grand Treks I'm afraid.

My economy is a bit worse since I fitterd the STs, but there could be other factors in that as well as I've changed my set up in other areas as well.
AnswerID: 224158

Reply By: meandet - Tuesday, Feb 27, 2007 at 08:54

Tuesday, Feb 27, 2007 at 08:54
Hi Gazman

We replaced the original Grand Treks on our 4Runner with Wrangler ATR's. As far as fuel use is concerned we don't know because we started towing a Tvan at the same time. I suspect however that they have increased fuel use. They are certainly much noisier, rougher and don't last as long as the Grand Treks. I was very happy with the Grand Treks, we did our first two trips with no problems. It was only that we were having trouble getting new Grand Treks in 205R16 without the need to fit tubes to them that we looked for alternatives in the first place.

Cheers Peter
AnswerID: 224263

Reply By: Sea-Dog - Tuesday, Feb 27, 2007 at 14:41

Tuesday, Feb 27, 2007 at 14:41
I don't think you will notice any difference in fuel economy just because you are going from the original rag bags to A/T tyres.. you will notice it however if you are increasing your tyre diameter / width etc as the rolling dimensions and weight are all changing..

Having made that comment I went from the standard 275/75/16 or whatever they are Grandtrek pieces of crap to a set of 305/70/16 BFG Muddies.. The fuel economy has suffered marginally (but it has suffered none the less) but I couldn't be happier..

The muddies now have over 40k on them and have at least half the tread depth left so I would be happy to get 70 or 80k out of them.. Noise wise they do have a bit so you would be happier with the A/T's although there are a lot out there on the market that come with their own road noise levels anyway.. there are HEAPS of threads on HEAPS of forums on which tyres are the best... I can say from experience that the Cooper STT's look to wear out very quickly...

Summing up... go for the A/T's or more aggressive if you are thinking of it.. don't worry too much about the fuel economy too much unless you are putting huge feet under your car... and enjoy!!
AnswerID: 224341

Reply By: Member - Bucky (VIC) - Thursday, Mar 01, 2007 at 09:37

Thursday, Mar 01, 2007 at 09:37
I fitted Cooper ATR's to my Navara, had a terrble job getting them to stop "tram-lining", they are almost impossible to stop them from following the camber of the road,,but they do follow the camber both sides, so in that respect, they are a true tyre.

Well 75,000 mkm later, I recon they are tough as.
Did the Simpson in 05, and back up to Innaminka, Walkers Crossing, Birdsville, Boulia an along the Plenty, into Alice in 06, and back out the Oodnadatta, via the Old Ghan railway line, and Chambers Pillar and Dalhousie. As you can see I am not easy on the tyres,, ( recon I fluked the tyre pressures ,, hehe ! )

There is still plenty of tread on them, and I have never had a puncture,

Seem to be getting harder in the sidewalls, could ride a bit better on the black stuff , but on gravell roads they shine.

Sure there are a few bits and pieces out of them, but I defy any tyre not to chip a little on the roads we went on .

Another point is that I rotate tyres every 5,000 km. This is a bit of a drag at times , but look at the Km's I have done, and then tell me I am wrong..

Cheers Mate
AnswerID: 224722

Follow Up By: Member - Bucky (VIC) - Thursday, Mar 01, 2007 at 09:41

Thursday, Mar 01, 2007 at 09:41
I did forget to tell you that I get 10 km / lt, normal travell and last trip with the camper averaged 6.6 km / lt.
Don't recon anything would do any better, as we were loaded up and towing our Trak Shak, camper,,

If foel economy is a real issue with you then pump up your tyres hard, and loose your ride.
Fow a few extra cents I recon its worth getting the ride !

Cheers again
FollowupID: 485675

Reply By: RichieK - Sunday, Mar 04, 2007 at 00:14

Sunday, Mar 04, 2007 at 00:14

2002 TD Prado here.
Currently on Cooper AT/R - Luv 'em - great on road , nice and quiet, good on gravel/dirt, haven't tried mud yet.
Previously had Wrangler AT/R - didn't like them on road, lumpy, noisy, squirmed like crazy. Saving them for offroad stuff (spare set of rims)
Previously to that had Grandtreks. I though they were ok till I got the Coopers.
Rolling dia seems the same - speedo/odometer still reading the same.

My fuel economy averages 11.5 l/100, mainly freeway driving. Yes, I've changed the air filter regularly. I used to achieve 10's, but something changed, not sure what - very frustrating

Cheers and beers
AnswerID: 225160

Follow Up By: Gazman - Monday, Mar 05, 2007 at 09:35

Monday, Mar 05, 2007 at 09:35
Thanks Rich. That's great feedback.

I'm guessing your economy dropped since you moved away from the GrandTrek's, or has it dropped since you moved away from the Wrangler's?

One final question: how many Km's have you done on the Cooper's and can you guess at what sort of life you might get out of them?

Cheers, Gary
FollowupID: 486264

Follow Up By: RichieK - Monday, Mar 05, 2007 at 16:02

Monday, Mar 05, 2007 at 16:02
Hi Gary

Fuel economy changed while I was still on the Grandtreks - very mysterious..
So far I've done 20000kms on the Coopers, I'm guessing they should be good for 60000?

FollowupID: 486342

Reply By: Gazman - Monday, Mar 05, 2007 at 09:38

Monday, Mar 05, 2007 at 09:38
Thanks to everyone that spent the time to post a reply. It seems like there's a lot of debate about tyres.

Still, if anyone out there has specifically gone from GrandTrek's to the new Cooper ATR, I'd still like to hear about your experience on fuel economy and noise.
AnswerID: 225361

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