Tires: Revs Per Mile + Odometer/Speedometer Question

[zeppelin]

I kinda like the idea of staying with the same size tires since that's what the car was engineered for...

But, I was just comparing the 265/65 Dunlops (stock) with the 265/65 Revos and noticed they have a different number for Revs/Mile.

The Dunlops are 711 Revs/Mile and the Revos are 603 Revs/Mile.

This confused me because it appears the overall tire diameters are almost exactly the same -- about 30.6".

1) Does anyone understand this discrepancy in Revs/Mile?

2) Also, would merely changing tread aggressiveness (highway --> off-road) affect your odometer or speedometer?

 

[Thai]

Wow...that's a significant difference. Is it a misprint?? Where did you see these numbers?? Have you looked at respective brand's website to confirm it??

 

[boston_kevin]

Yea, I see what you mean... Revo's and Dunflops seem to be out of range (Revo more so that Dunflop).. Goodyear, Michelin, BFG all seem to be in the 680 range (680-690) with Dunflops being closer at 711. Revos are really off at 603... I'm guessing that must be a misprint and should probably be 693 (due to the tire diameter)

 

[zeppelin]

Wow...that's a significant difference. Is it a misprint?? Where did you see these numbers?? Have you looked at respective brand's website to confirm it??

I got those numbers from tirerack.com. I was really confused by them, because that seems to be a huge discrepancy in revolutions being that they have equal diameters. Maybe it is a misprint.

I guess I will look at the respective sites for the actual tires.

 

[zeppelin]

Yea, I see what you mean... Revo's and Dunflops seem to be out of range (Revo more so that Dunflop).. Goodyear, Michelin, BFG all seem to be in the 680 range (680-690) with Dunflops being closer at 711. Revos are really off at 603... I'm guessing that must be a misprint and should probably be 693 (due to the tire diameter)

I just looked on Bridgestone's actual site, and it says 683. I guess tirerack has a typo.

I'm still curious how the difference even between 683 and 711 RPM would affect your gauges, though.

 

[Bluto]

I just looked on Bridgestone's actual site, and it says 683. I guess tirerack has a typo.

I'm still curious how the difference even between 683 and 711 RPM would affect your gauges, though.

Larger tire (revo) = speedo about 4% low. So at 60, you are actually traveling at 62.4.

And as any tire wears, RPM goes up.

 

[cpayne5]

Larger tire (revo) = speedo about 4% low. So at 60, you are actually traveling at 62.4.

And as any tire wears, RPM goes up.

Actually, the Revos are the smaller tire. It takes 28 more revolutions of the Revo to go the same 1 mile as the Dunlops. If the speedo says 60, you're actually going 57.5mph. Also, if you use 65 Revos for 100k miles, your odo will read 104k.

 

[Thai]

Ok...that's what i thought. TireRack occasionally makes mistakes in their stats.

 

[Bluto]

Actually, the Revos are the smaller tire. It takes 28 more revolutions of the Revo to go the same 1 mile as the Dunlops. If the speedo says 60, you're actually going 57.5mph. Also, if you use 65 Revos for 100k miles, your odo will read 104k.

No, think about it. : A larger circumference takes less revolutions to cover the same distance.

683 RPM is a larger circumference tire than 711 RPM.



Or look at Bridgestone's specs

The larger diameter tires have a lower RPM.

 

[Toyboomer]

tire revs and speedo

I just got off the phone with the Toyota dealer tire folks and and independent Big-O tire dealer about this fact. With my 06 Sport V-8 I'm thinking about going to a 265-70-17 vs. the stock 265-65-17, also in the Revo. The dealer assured me the only change would be a that my speedo would show approx. 65 when I was actually going about 63 or so.

I also inquired about the LT vs. the P tire. The P tire (std. SUV tire) is a four-ply and the dealer tire guy said he thought the handling would be a little better with the LT with a slightly stiffer ride. He said the LT was 6 ply and the Big-O rep said the LT can be obtained in a 6,8 or 10 ply. If I do this I would probably go with the 6 ply.

My other question for this post is whether, with a 1.1 inch larger tire circumfrence with 70 series Revo, would I need to replace the spare or could it be used short term? I'm fascilate between sticking with the stock size and P rated vs. going to the 70 series in either a P or LT series.

 

[pipspeak]

You would probably have to replace the spare... you'd potentially screw up the drivetrain if you run one different-sized tire.

Also bear in mind that the Revo's will probably hit your gas mileage a bit - larger tire and more aggressive tread with increased rolling resistance compared to the Dunflops, which are primarily road tires.

 

[cpayne5]

No, think about it. : A larger circumference takes less revolutions to cover the same distance.

683 RPM is a larger circumference tire than 711 RPM.



Or look at Bridgestone's specs

The larger diameter tires have a lower RPM.

I was thinking about it the same way you were, but I thought the Revo had the 711 number and not the 683 number. Doh. Minor case of dyslexia there for a minute.

Sorry if I confused anyone. The math was right, the mind wasn't. :bash:

 

[toybox]

Re: tire revs and speedo

The dealer assured me the only change would be a that my speedo would show approx. 65 when I was actually going about 63 or so.

It is the other way around. You are going faster than your speedo reads not slower.

 

[zeppelin]

I just looked at all the other best selling tires for the 06 Sport SE, and I noticed something odd.

The Revos (offroad A/T) as well as the other non-Dunlop highway all-season tires all had RPMs of about 683. The Dunlop is the only one that is up at 711.

I thought the difference was the offroad vs. highway, but the other highway best-sellers have similar RPMs to the Revo. I guess that supports the theory that the Dunlops are a bit smaller/wimpy.

 

[Toyboomer]

tire size

After these posts and speaking with several dealers I agree I should change the spare also if went to the 70 series. More money but then again maybe you save in the long run if you rotate 5 tires instead of 4. I usually leave my spare alone and rotate only 4 tires.

I'm still mulling going to a 70 series and the LT in a 6 ply. Like what Koz said about it.

Just got off the phone with the tire rep. at the Toyota dealer and he says the Revo is not made in the 65 series but I see it on the Bridgestone site, which he says he was looking at?? He said his rep. said that the LT was only made in 10 ply (vs. 4 for the P tire) and that I would definitely not want that kind of ride. So, he recommends I go with the 70 series in the P. Now, I'm really confused and will stop by the independent dealer this afternoon (50 mi. away).

 

[Koz]

The difference in revolutions is based on the overall diameter of the tire. The smaller the tire the more revolutions it makes. There is no rocket science here. The speedo may not be accurate from the factory. Most manufactures calibrate them to read slower at speed. You can see 1% error at slow speeds and several % at highway speeds. On motorcycles you can see up 10% error at speed. Handheld GPS systems will give a precise speed reading.

Koz