B330evo vs B391 tires=15 % difference in mpg.

windmill · 08-23-2006, 11:45 AM

Interesting data for Bridgestone B330evo users:

I have on the front side Bridgestone B330evo, and rear Bridgestone B391's.
Interesting is that I have an increase of 15 % in my fuelburn !
Normal I have an avarage of 90 mpg, now with the B330evo's 71 mpg.
Tire press is 43 psi- 3 bar.
I asked the supplier for data:

Weight B391: 5.8kg. Profiele depth:7.1 mm
Weight B330evo: 6.9kg. Profile depth:8.4 mm

Difference is 1.1 kilo per tire, I have only 2 evo's and that is causing already 15% more fuelburn

.

Next week I will be back with the OEM tires, the good old B391's.
The supplier also told me that the B391 is only develloped for the Insight.

Guillermo · 08-23-2006, 12:25 PM

Also take into consideration the difference in tire diameter/circumference.
It changes the fuel consumtion values displayed when different diameter tires are used because the speedometer and odometer readings are off.
The best way to confirm is to compare your speedometer with a GPS.
GPS is not very accurate at determining absolute position (+/- 10 to 30 feet it common) but it's fantastic at determining speed (+/- 0.2 km/hr is common).

windmill · 08-24-2006, 11:40 AM

Both tire sizes are 165-65-r14, so there is no diameter differential.
But it is thru that gps shows a 2% difference with the car's actual speed.

Guillermo · 08-24-2006, 02:31 PM

Check the actual diameter of the tires in the spec sheet. Just because they are both 165/65R14 doesn't mean they are exactly the same.
But because they are both the same brand they are likely very close in diameter.

Rick · 08-25-2006, 07:56 PM

To my knowledge the OEM tire on every Insight ever made is the Bridgestone Potenza RE92 165/65R14. The B381 is deffinitely a low rolling resistance tire as well (they used it on the 03-05 manual transmission Civic Hybrid), but I have seen no numbers to compare the two.

retepsnikrep · 09-12-2006, 02:35 PM

I had two 330 EVO tyres on the front of my Insight when I bought it, and it could never achieve quite the mpg of our other car, a 391 pattern shod Insight.

Replaced them today and mileage has gone up probably 5%.

Difficult to be exact but I recommend people do use the oem spec tyres.

RE-92 in USA

OR

391 IN UK.

Regards

Peter

ghillie · 09-12-2006, 06:53 PM

ret - in Australia the OEM tire (currently on my Insight) is also B391 165/65 R14 79T. Do you know if this is this the same tire as an RE 92 just with different names?

I need to replace the current tires and was thinking about the Michelin Energy XM 1 tires that are used on the Prius here. Any thoughts on comparable fuel economy?

retepsnikrep · 09-12-2006, 11:21 PM

I understand the RE92 and 391 are an equivalent pattern. Using any other tyre than oem is likely to reduce mpg.

Peter

Rick · 09-14-2006, 09:58 PM

Interesting, I do know the B381 is LRR certainly, but didn't know it was available in a 165 series... maybe just not in the state. Are they made in Japan? I know the 03-05 Civic hybrids with 5 speeds got the B381's, but those are a 185.

I learn something new every day.

**jack9994** · 09-15-2006, 07:51 AM

the first insight that came to the UK for technician training is still at Honda Institute - it has the B391 fitted - AFAIK the original tyres