Help me buy new tires please? :)

I've seen the same thing with the EP422's. They grab the grooves in the road terribly, and i've noticed a serious wobble when changing lanes at highway speed. I bought my '07 touring this summer, and it had Khumo Solus tires on it, which were run ragged already. I got the EP422 due to the recommendations on this site, but i've seen no MPG improvement what so ever and i've put about 1200 miles on them already. I'm averaging 40-42 overall with 90% of my miles being freeway, but pretty hilly. Am I doing something wrong? My touring has the stock 16" wheels, with the stupid covers ditched and Toyota center caps installed, other than that she's completely stock, and I consistently use Mobil 1 Full Synthetic, recommended weight of 5w 20.

 

Have you accounted for winter weather? You're not comparing warm weather mpg to cool weather mpg right? How worn were your Kumhos when you replaced them?

FWIW, the OE Yokohama S33D tires wander even worse than the EP422. My 17" EP422 didn't wander at all.

 

Well, I'm in Southern California, and I understand that cooler temps change things, but other than the occasional rainy day, I don't understand what I need to take into account. I drove in to work today, temps in the 60's, dry asphalt, and still averaged 41 on the trip, more downhill than up.

 

A 20F drop will affect mpg as will winter blend fuel. Well worn tires have a lower rolling resistance than when new. So it would take a super fuel efficient tire to provide and instant increase in mpg vs. an older worn tire. Sometimes the EP422 can do that but usually the only tire to provide such an instant increase is the Energy Saver A/S. I'm not saying you're wrong. There many variables to consider is all.

The fact is, had you bought the same exact Kumho tire as a replacement you would have observed an instant drop in mpg because the tire is new.

Tire Tech Information - Tire Rolling Resistance Part 3: Changes to Expect When Switching from Worn-Out to New Tires

 

Good to know...I've had these on for going on two weeks only, but I've put almost 1300 miles on already, being that my commute is 66 miles each way, lol. I just thought ditching the non LRR to switch to this should see some gain right off the bat. I'll keep tracking and post any relevant updates.

 

So what did you decide?

 

I would have thought you would see an increase but if your old tires were worn and the new ones didn't instantly drop you by 2mpg or more than you're in good shape.

Please keep us updated. I'm interested to see how they work in the 16" size. I know they are not a great handling tire but most people like them. What's your air pressure at? For decent handling I had my 205/50/17s at 44psi. At 35psi they were super mushy.

 

I noticed the same thing. When the shop mounted and balanced, they filled them to 35 and they appeared to have a belly. I saw some guys recommend 42/40 but I didnt want to push it until i ran the tires for a bit, so I put them at about 40/38. I need to buy an accurate tire gauge so that I don't have to rely on that little brass bobber thing on the air hoses. I was also trying to find a place to fill with Nitrogen, since it tends to expand and contract much less than regular air. On the old tires, i was monitoring my pressure weekly, and when we hit the big winter weather change, I saw a drop of about 3 psi from the temp change, so I'm checking them more frequently now, at least twice a week.

 

Not true I'm afraid. Normal air is 80% nitrogen any way but all gasses expand and contract at the same rate for a given temp change.