New Wheels and Tires: Photos, Mileage Impact (Long)
#1
04-06-2006, 07:15 PM
New Wheels and Tires: Photos, Mileage Impact (Long)
A few weeks ago, since it's started raining a lot in Southern California,
proved to be fairly scary as my too-worn-out OEM tires began slipping a lot on the freeway, only with careful throttle-feathering and steering did I manage to avoid completely hydroplaning. I knew that new tires were an absolute must. I couldn't get any good pictures until now due to weather, but today was nice and sunny, so I decided to snap a few and post them.
However, I, and most people in my family and friends have never liked the stock wheels on the '03 HCH, so now seemed like a good time to look into getting replacement wheels at the same time. After looking at tons of 15-16" wheels, I ended up especially liking the American Eagle 039 series 16" wheels. This model had the nicest spoke pattern of all the alloy wheels I was looking at, and came in chrome finish at a lower price than most similar looking silver painted wheels.
I looked around at trying to find some Low-Rolling-Resistance tires, though most of the ones that I found were either somewhat off from the original wheel diameter, or very expensive. I ended up settling on Kumho Ecsta 711s (205/50/16), nominally the same diameter as OEM. I would have preferred to get slimmer tires (195/55/16s was my first choice for tire size), but the selections in that size were few, and expensive. Ultimately though, I figured that the fuel savings from slightly reduced rolling resistance woudln't be able to come close to recouping $50+/tire over their lifetime.
Total cost was under $800 for wheels and tires, installed (Wheels were <$130, tires were <$70)
Here are a couple of my photos from the "Share" section:
In the beginning,fuel consumption was excessively higher, the car seemed to have noticably worse performance, and mileage was down by 20-25% (!!) over known stretches of driving. However, I noticed shifting into neutral had a massive effect when rolling at low speeds, as if there was a continuous load on the engine for some reason (about as significant as running the A/C compressor), which didn't make sense if the problem was rolling resistance and unsprung weight.
I did notice vastly superior handling of the car around turns, especially when wet, compared to the old tires. The car is actually a lot more fun to drive now when handling tight turns. With lots of rain, it was good timing replacing the tires. I would actually say that the wet handling on the Kumhos could almost beat the dry handling on the old Dunlops.
Anyway, things improved last weekend when I accidentally left the dome light on in the car and drained my 12v battery. I jumpstarted the car. State of Charge for the HV Battery was empty. On the way down the hill I live on, while charging, the SoC jumped from about ~1/2 to full at one point (Since the battery when at home is usually about 1/2 full, I gather that the Hybrid Pack wasn't actually drained).
Immediately, the vehicle performance improved noticably. I was getting much more assist, and had no more continual load on the engine. Accelerations were normal again (so the acceleration hit was not due to the extra unsprung wheel weight) I suspect the computer had lost track of the battery SoC, and wasn't charging it all the way, meaning it would give assist for a short time, then go back to parasitic charging. It's quite possible I actually had this problem since even before getting the new tires, (I didn't track mileage closely just before then) but only noticed it when I was paying attention to mileage with the new wheels.
The mileage hit over known stretches went from 25-20% to a 10% just like that (445 instead of 50mpg) . Then I considered another thing -- the old tire treads were worn almost completely down, which would have caused the actual tire diameter to be lower before, meaning that my most recent mielage readings would have been falsely optimistic. Measuring each tire indicated about a 4% tire diameter increase with the new ones. Thus, actual mileage seems to be somewhere in the ballpark of 6% worse with the new tires and wheels. (45 instead of 48mpg)
NOTE: Mileage data is very sketchy as this point, due to my inconsistent mileage records, weather, and thousands of other uncontrolled variables, though my estimate of 6% actual difference seems about right.
proved to be fairly scary as my too-worn-out OEM tires began slipping a lot on the freeway, only with careful throttle-feathering and steering did I manage to avoid completely hydroplaning. I knew that new tires were an absolute must. I couldn't get any good pictures until now due to weather, but today was nice and sunny, so I decided to snap a few and post them.
However, I, and most people in my family and friends have never liked the stock wheels on the '03 HCH, so now seemed like a good time to look into getting replacement wheels at the same time. After looking at tons of 15-16" wheels, I ended up especially liking the American Eagle 039 series 16" wheels. This model had the nicest spoke pattern of all the alloy wheels I was looking at, and came in chrome finish at a lower price than most similar looking silver painted wheels.
I looked around at trying to find some Low-Rolling-Resistance tires, though most of the ones that I found were either somewhat off from the original wheel diameter, or very expensive. I ended up settling on Kumho Ecsta 711s (205/50/16), nominally the same diameter as OEM. I would have preferred to get slimmer tires (195/55/16s was my first choice for tire size), but the selections in that size were few, and expensive. Ultimately though, I figured that the fuel savings from slightly reduced rolling resistance woudln't be able to come close to recouping $50+/tire over their lifetime.
Total cost was under $800 for wheels and tires, installed (Wheels were <$130, tires were <$70)
Here are a couple of my photos from the "Share" section:
In the beginning,fuel consumption was excessively higher, the car seemed to have noticably worse performance, and mileage was down by 20-25% (!!) over known stretches of driving. However, I noticed shifting into neutral had a massive effect when rolling at low speeds, as if there was a continuous load on the engine for some reason (about as significant as running the A/C compressor), which didn't make sense if the problem was rolling resistance and unsprung weight.
I did notice vastly superior handling of the car around turns, especially when wet, compared to the old tires. The car is actually a lot more fun to drive now when handling tight turns. With lots of rain, it was good timing replacing the tires. I would actually say that the wet handling on the Kumhos could almost beat the dry handling on the old Dunlops.
Anyway, things improved last weekend when I accidentally left the dome light on in the car and drained my 12v battery. I jumpstarted the car. State of Charge for the HV Battery was empty. On the way down the hill I live on, while charging, the SoC jumped from about ~1/2 to full at one point (Since the battery when at home is usually about 1/2 full, I gather that the Hybrid Pack wasn't actually drained).
Immediately, the vehicle performance improved noticably. I was getting much more assist, and had no more continual load on the engine. Accelerations were normal again (so the acceleration hit was not due to the extra unsprung wheel weight) I suspect the computer had lost track of the battery SoC, and wasn't charging it all the way, meaning it would give assist for a short time, then go back to parasitic charging. It's quite possible I actually had this problem since even before getting the new tires, (I didn't track mileage closely just before then) but only noticed it when I was paying attention to mileage with the new wheels.
The mileage hit over known stretches went from 25-20% to a 10% just like that (445 instead of 50mpg) . Then I considered another thing -- the old tire treads were worn almost completely down, which would have caused the actual tire diameter to be lower before, meaning that my most recent mielage readings would have been falsely optimistic. Measuring each tire indicated about a 4% tire diameter increase with the new ones. Thus, actual mileage seems to be somewhere in the ballpark of 6% worse with the new tires and wheels. (45 instead of 48mpg)
NOTE: Mileage data is very sketchy as this point, due to my inconsistent mileage records, weather, and thousands of other uncontrolled variables, though my estimate of 6% actual difference seems about right.
#2
04-06-2006, 08:00 PM
Re: New Wheels and Tires: Photos, Mileage Impact (Long)
Very nice -- the wheels and tires enhance the look of your car quite a bit! And thanks for the detailed analysis of the MPG effects as well.
It's ironic that you and I both killed our 12v battery in the same week. Must have been a bad week to be a battery in a hybrid car. I have not noticed any change in my IMA behavior, but I will be on the lookout for it.
It's ironic that you and I both killed our 12v battery in the same week. Must have been a bad week to be a battery in a hybrid car. I have not noticed any change in my IMA behavior, but I will be on the lookout for it.
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