How wheel & tire size and style affect Mirage fuel economy/mileage

[chris2004]

what ET in15" Alloy

in thailand have 14" Alloy Only

The GLS Attrage has 15in alloy wheels in Thailand

[Dorifuta]

So does anybody know of a company that makes build-to-order steel wheels? I'm interested in having a set of 15x4's made.

[Canoehead]

So it seems in Canadian Spec - the Mirage comes base with steel wheels, or SE with alloys - same tire size used on both. Are the steel wheels still more efficient because of the drag? Wouldn't the alloys be lighter?

I don't want alloys, but am considering the SE for the air conditioning, and the local dealer seems to have several in stock - might be some room to move on the price.

[MetroMPG]

I'd like to see a comparison of the weight of the steelies vs. alloys. (I'd be surprised if it isn't already posted somewhere in here.)

That said, aero trumps weight.

You can always add a smooth disc to the alloy wheel, though it's more difficult. 3dplane did it to his Mirage's alloys: Smooth wheel covers

[deleted user]

Something not mentioned (read the whole thread) is tread depth. The Ensaves on my Mirage were 8/32nds inch when new. Most tires have significantly deeper grooves when new, in the range of 11-12 32nds, so an additional 50% of tread area rubber meeting the road surface.

Since RR drops as a tire wears, shaving the extra 4/32nds of rubber off the tire would increase the RR and reduce the tread life, which explains the shorter life and lower RR of dedicated RR tires (not the only difference but very significant).

This is true of the Bridgestone RE92s which were specific to the 1st gen Insight (also owned one). IT is also true of the ORIGINAL Bridgestone tires on the 92-95 Civic VX (owned one of those as well).

My VX (with 28,472 miles when purchased totalled in 2008) had the OE Bridgestones when I bought it it and their tread wear rating was below 400. When I changed them to Michelin X the mpg dropped by 7 mpg. The orignal tires were dry rotted at 15 years age (date coded march of 93).

The Dunlop Ensaves on my Mirage, with 0 toe and decent camber on the rear axle are among the best coasting tires I have ever owned, including the VX and 1st gen Insight. My test, although not as precise as Metros, consists of coasting .3 mile from the entance to my neighborhood to the top of my driveway. If I can hit the turn at 23 mph I can get to the driveway at about 16 mph, due to a slight downhill grade (including two turns).

I could not do that in the VX or Insight, but the Mirage, with proper alignment and 50psi in the tires, will do that.

I did not run that high a pressure in the Insights RE92s and certainly did not in the 15 year old tires on the VX which were rated for only a 38 psi max pressure.

regards
mech

[cyclopathic]

IMHO it is a testimony to how good Enasaves are. I'll bet the Brigestones which they use in 15" are the reason.

I had looked at EU efficiency labels for several brands, and there is almost no difference with such size delta.

[MetroMPG]

The Dunlop Ensaves on my Mirage, with 0 toe and decent camber on the rear axle are among the best coasting tires I have ever owned, including the VX and 1st gen Insight.

I would love to do a direct comparison and am hoping to get the chance one day. I still have a set of RE92's (though they're older & pretty much worn out, so they would have a rolling resistance advantage over a newer set of Enasaves).

Maybe someone at InsightCentral has already done a comparison by now. I know some Insight owners were interested to hear about the Mirage's OEM tire becoming available in the U.S. because of occasional rumours that the OEM RE92 is going to be discontinued.

[deleted user]

I would love to do a direct comparison and am hoping to get the chance one day. I still have a set of RE92's (though they're older & pretty much worn out, so they would have a rolling resistance advantage over a newer set of Enasaves).

Maybe someone at InsightCentral has already done a comparison by now. I know some Insight owners were interested to hear about the Mirage's OEM tire becoming available in the U.S. because of occasional rumours that the OEM RE92 is going to be discontinued.

When I replaced the RE92s on my Insight, with new ones, I saw no change in mileage to the point where it would be obvious on my fuel log. I thought that was remarkable. My lifetime average with a CVT was 67 mpg over the 30k miles I owned that car.

My opinion (worth what you paid for it) is the two tires would be very close in RR, possibly within 1%.

regards
mech

[cyclopathic]

I would love to do a direct comparison and am hoping to get the chance one day. I still have a set of RE92's (though they're older & pretty much worn out, so they would have a rolling resistance advantage over a newer set of Enasaves).

Maybe someone at InsightCentral has already done a comparison by now. I know some Insight owners were interested to hear about the Mirage's OEM tire becoming available in the U.S. because of occasional rumours that the OEM RE92 is going to be discontinued.

To do a fair comparison you need a ramp or a hill to do roll out, and preferably more than one car to eliminate alignment/brake drag difference.

[MetroMPG]

Yup, I used a slight hill in a nearby parking lot for the roll-out. Also I attempted to avoid possibly variable disc brake drag by not using the hydraulic brakes at all before / during the comparison (while moving the car around/changing wheels etc). I only used the handbrake (drum style).