Anybody running Avon M550 Tech 235/50-17 All-Weather tires on their sedans that have noticed a distinct drop in fuel mileage? I love the tires, and they are a HUGE improvement over the stock RS-A's, but it seems like I am getting a lot worse gas mileage. Why?

 

Never even heard of them...?

 

Had the opposite effect on my sister's car. MPG went up significantly.

 

Hmm, I'll have to check - I have the same tires in the same size. I haven't noticed a big difference but I can't say I've checked either. I've had these tires for about 6 months now. I'll have to check next time.

 

It's because the 235/50R17s Avon M550 weigh 5lbs more a piece than the OEM spec 215/55R17 Avon 550. The 235s also have a 1" wider contact patch. Adding 5lbs in rotational weight, especially weight furthest from the hub, is the absolute worst weight you can add to a car. The additional tread width doesn't help either. I wouldn't be surprised if MPG was impacted by 2mpgs or so.

http://www.tirerack.com/tires/Spec.j...e1=yes&place=0

215/55R17 26lbs, tread width 7.6", section width 8.9"

235/50R17 31lbs, tread width 8.6", section width 9.5"

 

I have them in 245/45/18 from the stock turanza 215/55/17. I think mpg is about the same. It's horrible to begin with. Till today I get about 17 mpg . My friend's Honda Pilot gets better mpg than my car. Go figure...the pilot is like 4,000+ lbs I think.

 

But Bobby, the G is a lot more fun to drive than a ho-hum Pilot .
Excellent points made by DaveB as to why the MPG difference.

 

Wayne...true true

Yeah, it's hell more fun than a pilot of course. That thing floats on the highway like there's no tomorrow. Doesn't feel safe at all...

 

I had the 550's in stock 215/55/17 and had no difference in MPG. The 225/45/18 Yoko's are about .5" smaller in ID and no difference there either. Gets 22-24 MPG every fillup.

 

No difference here. I went from Goodyear Eagle GS-D to Avon M550 A/S. The only complaint I have about the 550 is the weak sidewalls (the car exhibits more body roll in the 550s). Both tires were 215/55 on the sport suspension (2004) 17" rims.

 

Just a thought, check your tire pressures.

 

Tires are on 37-lbs. which I increased from the 32-lbs. the installer put in to "lighten" the streering a little. I just checked the pressure yesterday, and all is well. The tires "feel" noticeably heavier, and the steering response is a little slower so the more rolling mass = less fuel mileage makes some sense. I am not sure how much worse the mileage is, but I'll bet it's down 4mpg or so.

 

A lot of that stems from the fact that the GS-Ds are summer-based true high performance rubber. The 550s have to handle the snow so the rubber compound, tread, and often times the sidewall strength is compromised. I'd love to get summer hi-po tires, but I can't thanks to the 15-30" of snow we get every year.

 

I use to have Avon Tech 550 AS on my 17 sports and got about 22/23 mpg per fill up. Not bad!

 

My previous car had Michelin tires OEM a low rolling resistance tire. I replaced them with a high performance summer tire and my gas mileage dropped 10% but my smile factor went up 100%. High performance tires have a larger tire patch and higher rolling resistance. It's all a trade off.

'06 G35X stock in Philly.