Horrible Gas Mileage...WHY?!
10-11-2013, 08:24 AM
#41
Registered User
Thread Starter
Join Date: Apr 2008
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
I hate being the bearer of bad news, but I too was under this assumption with my tires and found out otherwise.
If you have an SR5, they came with 31" tires, much like the Taco's after them. Not all models, but the SR5's did. I currently have 225/75 R15's, what the "books" say the truck should have. Here's my discovery: https://www.yotatech.com/forums/f116...nfused-272221/
Basically, if you drop lower than 31's your tires are spinning more per mile and giving a false reading. Your MPH's and MPG's are inflated by 9%. For example, a recent road trip was 91 miles, and my odometer read 100 by the end. GPS says 63 MPG, speedometer reads 70. Use a smartphone or GPS that reads MPH and you'll see what I mean.
If you have an SR5, they came with 31" tires, much like the Taco's after them. Not all models, but the SR5's did. I currently have 225/75 R15's, what the "books" say the truck should have. Here's my discovery: https://www.yotatech.com/forums/f116...nfused-272221/
Basically, if you drop lower than 31's your tires are spinning more per mile and giving a false reading. Your MPH's and MPG's are inflated by 9%. For example, a recent road trip was 91 miles, and my odometer read 100 by the end. GPS says 63 MPG, speedometer reads 70. Use a smartphone or GPS that reads MPH and you'll see what I mean.
Also, I have a double-din radio with navigation, and use it often. According to it, I am going exactly what my speedometer says; when I had the 235s from my old steel wheels, it always read +2 MPH faster. I always found that odd since 235s were the stock tire size my truck came with...
10-11-2013, 09:37 AM
#42
Registered User
You might be ok then. Your truck might have had the gear ratios changed or the speedo changed to accomodate the larger/smaller tires (or maybe yours was actually set up for 225/75 R15s). That 2 MPH different is what I mean, so it seems like your truck is geared for the exact size you have.
So in your case, it was flipped. The old tires you had were giving a false reading in the opposite, you were actually going more miles and getting better gas mileage than you thought!
So in your case, it was flipped. The old tires you had were giving a false reading in the opposite, you were actually going more miles and getting better gas mileage than you thought!
Thread
Thread Starter
Forum
Replies
Last Post
justdifferentials
Vendors Build-Ups (Build-Up Section)
14
06-11-2017 08:36 PM
Tcsdef
General Electrical & Lighting Related Topics
1
09-07-2015 11:17 PM
