KO2 C1 vs E1

So I ordered a stock size 265/70/17 C1 BFGoodrich KO2, and got it installed today. I test drove on the highway for nearly an hour under my normal driving habit and I only got 16.5 mpg ... I normally get 20mpg.

When I reached home, I inspected the tires and to my surprise, they installed the heavier and beefier E1 which weighs 6lbs more per tire.

My question, will there be a significant difference in "mpg" when comparing the C1 against E1?

Don't laugh at me, I am not yet going rock climbing, this vehicle is currently a mall crawler, and used for long drives. I just like the look of the KO2's.

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Edit:
Picture below was taken when I reached home, trying to figure out how to solve this... Google map says from home to highway exit is 10.5miles/18 minutes, multiply that by 2 because I started from home, then back = 36 minutes city drive. My total drive was 52 minutes, so 16 minutes was spent on the highway. So combined highway/city of 15.8 mpg. I got to say though, the A/C was on full crank (look at the outside temp)... I am overthinking this, LMAO

 

Not enough to make a notable difference in your pocket.

 

I don't think Load E will have such a big difference. Here's a non scientific test for 20miles of highway drive giving me stock mpg with 275 Load E KO2 + OME 2.5” lift + RSG sliders.

Also note this is pre 2020 instrument cluster. My newer 2021 instrument cluster show me much lower mpg but when I calculate by hand the real mpg is much better. But just wanted to say 275/70R17 Load E did not give me bad mpg. Just my experience. Hope your alignment is good.

https://youtu.be/Km9Lb1SKxn8

 

Significant? Maybe not. But, it will certainly make a difference.

If fuel economy is a concern, I would have stuck to the SL version. C is a nice compromise. But, if you're not getting into situations where puncture resistance is a consideration, LT tires are probably overkill.

 

If you requested and paid for C's then the shop should fix the problem. Yes, 6 pounds per wheel assembly, especially at the tire, will make a difference in MPG, acceleration and braking performance. I swapped wheels last month and went from a 25 pound Motegi to a 21 pound Konig and my MPG increased from 17.8 average to 20.1 average using the same 255/75 KO's.

 

E is way overkill for our light 4Runners. Ride quality will improve also with the C’s.

 

So they changed the tires to C1, but my steering wheel is vibrating... now they are trying to check everything again... my luck !

 

Do they have roadforce balance machine to properly balance the wheels & tires?
Is it a good tire shop that maintains and calibrate the roadforce balance machines?

Edit -

a sample pic-

 

Yeah they did a road force balance and they put the tires on the rear. I drove it as is and it didn't vibrate but I rotated the tires and there is a little vibration, I am now at Discount tires, they will replace one tire... and hopefully that will solve the issue.

 

I’ve never been a fan of white letters showing, but I’ve got to say they look great on the Nautical Blue!

 

Careful, don’t you dare blame the tires…sacred ground around here.

 

I’ve had my stock sized c rated k02’s rebalanced 3 times, had an alignment, and had Toyota look at it and claim it’s fine. Still have the wheel shimmy. Many, MANY others experiencing the same shit. I’m about to return the tires and get something else.

 

If it makes you feel better, I had the shimmy when I first got the 4Runner brand new. i just ignored it. Now I'm just picky because of the KO2's. So far after road force balance, and Discount tires changing the really bad ones, no more shimmy...

 

E tires are absolutely great, but a waste if you don't off-road at all.

Like mentioned, if you paid for 'C' rated you should get what you paid for. They probably just had a set of 'E' rated sitting somewhere and slapped them on which would make me inspect the date code to ensure I didn't get a set of older tires.