I'd think that new tires = greater traction = less mileage
but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. Can new tires really make it drop that much? I had old tires that would barely pass inspection, and then just put on new all season Yoko Avid TRZs (which are not M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil before the trip, too.
Another factor was a CEL code of P0442 that had been registered a couple weeks ago: http://www.obd-codes.com/p0442 "EVAP small system leak"
The CEL had been on for a while, but since I disconnected the battery today, it has stayed off - so I'd suspect it was transitory (gas cap?), even though the CEL never turned itself off.
> I'd think that new tires = greater traction = less mileage
> but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. Can new > tires really make it drop that much? I had old tires that would barely pass > inspection, and then just put on new all season Yoko Avid TRZs (which are not > M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil before the > trip, too.
> Another factor was a CEL code of P0442 that had been registered a couple weeks > ago:http://www.obd-codes.com/p0442 > "EVAP small system leak"
> The CEL had been on for a while, but since I disconnected the battery today, > it has stayed off - so I'd suspect it was transitory (gas cap?), even though > the CEL never turned itself off.
disconnecting the battery doesn't erase the codes. You need a code reader for that.. check the gas cap gasket for cracks. If it has any replace it.
Tom wrote: > I'd think that new tires = greater traction = less mileage
> but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. Can new > tires really make it drop that much? I had old tires that would barely pass > inspection, and then just put on new all season Yoko Avid TRZs (which are not > M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil before the > trip, too.
> Another factor was a CEL code of P0442 that had been registered a couple weeks > ago: > http://www.obd-codes.com/p0442 > "EVAP small system leak"
> The CEL had been on for a while, but since I disconnected the battery today, > it has stayed off - so I'd suspect it was transitory (gas cap?), even though > the CEL never turned itself off.
Well, were the new tire exactly the same size as the old ones? Even saying they were the same size and model of tire, the new tread height means the new tire travels farther per revolution that the old worn out one did which makes the subjective gas mileage 'seem' lower. You are actually driving farther now than the odometer thinks, compared to the worn out tires.
The way to tell for sure is to use a GPS or a measured mile to check your odometer for accuracy.
Mike 2000 Cherokee Sport 86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00 'New' frame and everything else in '09. Some Canadian Bush Trip and Build Photos: http://mikeromainjeeptrips.shutterfly.com
Tom wrote: > I'd think that new tires = greater traction = less mileage
> but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. Can new > tires really make it drop that much? I had old tires that would barely pass > inspection, and then just put on new all season Yoko Avid TRZs (which are not > M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil before the > trip, too.
The rolling resistance of tires does vary, though that seems like a very big change. I would not expect that much of a change unless you changed to very wide, or very agressive tread tires. More and more mfgs are offering high milage (low resistance) tires, but it will be awhile before they are mainstream.
Don Stauffer wrote: > Tom wrote: >> I'd think that new tires = greater traction = less mileage
>> but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. >> Can new >> tires really make it drop that much? I had old tires that would barely >> pass >> inspection, and then just put on new all season Yoko Avid TRZs (which >> are not >> M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil >> before the >> trip, too.
> The rolling resistance of tires does vary, though that seems like a very > big change. I would not expect that much of a change unless you changed > to very wide, or very agressive tread tires. More and more mfgs are > offering high milage (low resistance) tires, but it will be awhile > before they are mainstream.
I see tons of vehicles equipped with Michelin "Green X" tires, although how "low" their rolling resistance really is compared to a "normal" tire I don't know.
Don Stauffer wrote: > Tom wrote: >> I'd think that new tires = greater traction = less mileage
>> but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. >> Can new >> tires really make it drop that much? I had old tires that would barely >> pass >> inspection, and then just put on new all season Yoko Avid TRZs (which >> are not >> M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil >> before the >> trip, too.
> The rolling resistance of tires does vary, though that seems like a very > big change. I would not expect that much of a change unless you changed > to very wide, or very agressive tread tires. More and more mfgs are > offering high milage (low resistance) tires, but it will be awhile > before they are mainstream.
I should also say that low friction tires would affect highway milage a lot more than city driving. In highway milage the energy losses are primarily dissipative, like rolling and wind resistance, while a large percent of city driving goes into increasing kinetic energy and then destroying it with brakes.
Don Stauffer wrote: > Tom wrote: >> I'd think that new tires = greater traction = less mileage
>> but my 2002 3.1L Buick Century V6 went from ~32mpg to ~27mpg hiway. >> Can new >> tires really make it drop that much? I had old tires that would barely >> pass >> inspection, and then just put on new all season Yoko Avid TRZs (which >> are not >> M+S), before a 200 mile trip. Tire PSI is good. I'd changed the oil >> before the >> trip, too.
> The rolling resistance of tires does vary, though that seems like a very > big change. I would not expect that much of a change unless you changed > to very wide, or very agressive tread tires. More and more mfgs are > offering high milage (low resistance) tires, but it will be awhile > before they are mainstream.
yes, a big change. I guess another trip might some week be informative.
Btw, does it follow that high mileage tires would have less rain/snow traction? Just curious.
|
